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7820A Advanced User Guide

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1. This function can only be done by Agilent service personnel 3 Scroll to Auto prep run Press On Yes to enable Auto prep run Off No to disable it See Pre Run and Prep Run on page 110 for details 4 Scroll to Zero Init Data Files Press On Yes to enable it When it is On the GC immediately begins to subtract the current detector output from all future values This applies only to digital output and is useful when a non Agilent data system has problems with baseline data that is non zero Press Off No to disable it This is appropriate for all Agilent data systems 5 The Oven line displays the GC power configuration 6 Press Clear to return to the Config menu or any other function to end Advanced User Guide Agilent 7820A Gas Chromatograph Advanced User Guide 4 Options About Options 44 Calibration 45 Maintaining EPC calibration inlets detectors and PCM 45 Auto flow zero 45 Zero conditions 46 Zero intervals 46 To zero a specific flow or pressure sensor 46 To zero all pressure sensors in all modules 47 Column calibration 47 Communication 51 Configuring the IP address forthe GC 51 Keyboard and Display 52 Ee Agilent Technologies 43 4 Options About Options 44 The Options key is used for a group of functions that are usually set on installation and seldom changed afterward It accesses this menu Calibration Communication Keyboard and Display Advanced User Guide Opt
2. inj position number of injections at each position 0 99 Position rng first last valve positions to sample 1 32 Times thru range number of times to repeat the range 1 99 injections number of injections for each sample 4 Proceed with step 5 of To program a sequence on page 83 To program post sequence events 1 See step 1 through step 4 of To program a sequence on page 83 2 Scroll to the Method line of Post Sequence and enter a method number Use 1 to 9 for the stored methods or 0 if there is no method to be loaded 3 Press On Yes at Repeat sequence to keep repeating the sequence useful for valve sequences Otherwise press Off No to halt the sequence when all subsequences are finished Advanced User Guide 85 6 86 Methods and Sequences To save a sequence 1 2 3 Press Store Seq Enter an identifying number for the sequence Press 0n Yes to store the sequence Alternatively press Off No to cancel A message is displayed if a sequence with the number you selected already exists Press On Yes to replace the existing sequence or Off No to cancel Sequences can also be stored from within the stored sequence list Seq by scrolling to the appropriate sequence number and pressing the Store key To load a stored sequence Press Load Seq Supply the sequence number and press Enter The specified sequence will replace the current active sequence
3. 3 Replace consumable parts liner septum traps syringe and so forth as needed for the checkout See To Prepare for Chromatographic Checkout 4 Verify that the Lit Offset is set appropriately Typically it should be about 2 0 pA for the checkout method 5 Install the evaluation column See the procedure for the SS or PP in the Maintenance manual Set the oven inlet and detector to 250 C and bake out for at least 15 minutes See the procedure for the SS or PP in the Maintenance manual Be sure to configure the column Advanced User Guide Advanced User Guide Phosphorus performance Chromatographic Checkout 5 6 If it is not already installed install the phosphorus filter 7 Create or load a method with the parameter values listed in Table 7 Table 7 FPD Checkout Conditions P Column and sample Type Sample Column mode Column pressure Split splitless inlet Temperature Mode Purge flow Purge time Packed column inlet Temperature Detector Temperature Hydrogen flow Air Oxidizer flow Mode Makeup flow Makeup gas type Flame Lit offset High voltage Oven Initial temp Initial time Rate 1 HP 5 30 m x 0 32 mm x 0 25 um 19091J 413 FPD checkout 5188 5953 Constant pressure 25 psi 200 C Split splitless Splitless 60 mL min 0 75 min 200 C 200 C On 75 mL min On 100 mL min On Constant makeup flow OFF 60 mL min On Nitrogen On Typica
4. 30 m x 0 32 mm x 0 25 pm 19091J 413 FID checkout 5188 5372 6 5 mL min Constant flow 250 C Splitless 40 mL min 0 5 min Off 250 C 300 C 30 mL min 400 mL min 25 mL min Typically 2 pA 75 C 0 5 min 20 C min 190 C 0 min 57 5 58 Chromatographic Checkout Table 3 FID Checkout Conditions continued Sample washes Sample pumps Sample wash volume Injection volume Syringe size Solvent A pre washes Solvent A post washes Solvent A wash volume Solvent B pre washes Solvent B post washes Solvent B wash volume Injection mode Airgap Volume Viscosity delay Inject Dispense Speed 7693A Prelnjection dwell PostlInjection dwell Manual injection Injection volume Data system Data rate 2 6 8 Tul 10 uL co oOo O N N Normal 0 20 0 6000 1 uL 5 Hz 8 If using a data system prepare the data system to perform one run using the loaded checkout method Make sure that the data system will output a chromatogram If not using a data system create a one sample sequence using the GC keypad 9 Start the run If performing an injection using an autosampler start the run using the data system or press Start on the GC Advanced User Guide FID1 A C FID D 400 350 300 250 200 150 100 50 Chromatographic Checkout 5 If performing a manual injection with or without a data system a Press Prep Run to prepare the inlet for sp
5. Editing events inthe runtable 15 Deleting runtime events 16 Clock Time Programming 17 Using clock time events 17 Programming clock time events 17 Adding events to the clock table 18 Editing clock time events 18 Deleting clock time events 18 Post Run Programming 19 Ee Agilent Technologies 2 Programming Run Time Programming Run time programming allows certain setpoints to change automatically during a run as a function of the chromatographic run time Thus an event that is programmed to occur at 2 minutes will occur 2 minutes after every injection Its uses include e Controlling column switching or other valves e Changing analog signal definition zero or range e Controlling an auxiliary pressure channel e Changing polarity of a thermal conductivity detector TCD e Turning the hydrogen flow to a nitrogen phosphorus detector NPD on or off e Switching digital signal output requires an Agilent data system e Pausing freezing and resuming digital signal output requires an Agilent data system The changes are entered into a run table that specifies the setpoint to be changed the time for the change and the new value At the end of the chromatographic run most setpoints changed by a run time table are returned to their original values Valves can be run time programmed but are not restored to their starting position at the end of the run You must program the reset operation in the run table if this
6. Front Inlet or Back Inlet Turn gas saver On Set Gas saver flow It must be at least 15 mL min greater than the column flow If in split mode set Savertime after injection time In all other modes set after Purge time 109 8 inlets Pre Run and Prep Run With some inlets and operating modes certain instrument setpoints are different between runs than during an analysis To restore the setpoints for injection you must place the GC into the Pre Run state You must use the Pre Run state when e Using gas saver with any inlet e Using splitless mode with any inlet e Using a pressure pulse mode with any inlet There are three ways to begin Pre Run manually press Prep Run before each run on the GC keypad or software keypad automatically for Agilent samplers or using Auto Prep Run for non Agilent samplers The three methods are discussed below During the Pre Run state e The Run light blinks on the GC and the Pre Run indicator lights on the software keypad e Setpoints change to the correct values for injection e Inlet detector and oven equilibration times begin When all criteria for a run are met the Not Ready light turns off The GC is now ready for sample injection The Prep Run key 110 Press Prep Run before you inject a sample manually The GC enters the Pre Run state When the Run light stops blinking and the Not Ready light goes off begin the analysis Agilent samplers If
7. Heating the valves 178 Valve temperature programming 178 Valve Control 179 The valve drivers 179 The internal valve drivers 179 Valve Types 181 Configuring a Valve 182 Controlling a Valve 183 From the keyboard 183 From the run or clock time tables 183 Gas sampling valve 183 Ee Agilent Technologies 177 11 Valves The Valve Box The GC holds up to two valves in a heated valve box on top of the oven The valve box is the preferred location for valves because it is a stable temperature zone isolated from the column oven Back of chromatograph Valve heater block Valve box cover removed Figure 4 Diagram of valve locations on GC Heating the valves The valve box contains a heated block with two valve mounting locations shaded in Figure 4 The middle hole on each block is used to pass tubing into the column oven If two valves are used they share the same temperature setpoint Valve temperature programming 178 Most valve applications are isothermal however you can define three temperature ramps if desired Program this ramp the same as an oven ramp Refer to Setting the oven parameters for ramped temperature on page 132 for more information Advanced User Guide Valve Control Valves 11 Valves can be controlled manually from the software keyboard or as part of a clock or run time program Note that sampling valves automatically reset at the end of a run The valve drivers Tab
8. Inlets 8 Table 12 Heater connection locations by module continued Module Available heater connection location Aux heater 1 5 Front FPD uses heater connectors 3 and 5 Back FPD uses heater connectors 4 and 5 Advanced User Guide 113 8 inlets About the Split Splitless Inlet This inlet is used for split splitless pulsed splitless or pulsed split analyses You can choose the operating mode from the inlet parameter list The split mode is generally used for major component analyses while the splitless mode is used for trace analyses The pulsed splitless and pulsed split modes are used for the same type of analyses as split or splitless but allow you to inject larger samples Septum tightening S SL Septum retainer nuts must be tightened enough to obtain a good gas seal but not so much as to compress the septum and make it difficult to push a syringe needle through it For the standard septum retainer nut an internal spring in the septum retainer applies pressure to the septum For inlet pressures up to 100 psi tighten the retainer until the C ring lifts about 1 mm above the top surface This is adequate for most situations cere With higher inlet pressures tighten the septum retainer until the C ring stops turning indicating that the retainer is in firm contact with the septum If using a Merlin Microseal septum finger tighten the septum nut until snug not loose The pressure capacity depends on
9. Restrictor Wavelength filter 1 l J l 1 l Window l l l l Column The current from the PMT is amplified and digitized by the FPD electronics board The signal is available either as a digital signal on the communications output or as a voltage signal on the analog output The FPD should not be stored at temperatures above 50 C based on the original manufacturer s specifications for the PMT 171 10 Detectors 172 FPD linearity FPD Lit Offset Several mechanisms produce sulfur emission The excited species is diatomic so that emission intensity is approximately proportional to the square of the sulfur atom concentration The excited species in the phosphorus mode is monatomic leading to a linear relationship between emission intensity and atom concentration The default Lit Offset is 2 0 pA Starting Up and Shutting Down the FPD The FPD creates a great deal of water vapor when the flame is on This could condense in the vent tube on top of the detector and drop onto the flame possibly extinguishing it To avoid this turn the heaters on wait 20 minutes for the vent to heat up and then ignite the flame Water vapor will now make it over the top of the vent tube before condensing For similar reasons extinguish the flame before turning the heaters off FPD photomultiplier protection The PMT is extremely sensitive to light Always turn the PMT voltage off which turns off the high voltage to t
10. gases to an FID FINLET OK 68 watts 21 7 This heater is connected to the front inlet Status OK meaning that it is ready for use At the time that the GC was turned on the heater was drawing 68 watts and the inlet temperature was 21 7 C F DET SIGNAL FID The signal board for the front detector is type FID Unconfigured Accessory devices requiring GC power or communication must be assigned these GC resources before they can be used To make this hardware element usable first Unlock the GC Configuration on page 24 then go to the Unconfigured parameter and press Mode Type to install it If the hardware element you are configuring requires selection of additional parameters the GC asks for that selection If no parameters are required press Enter at the GC prompt to install that element You are required to power the GC off and then power the GC on to complete this configuration After restarting the GC a message reminding you of this change and its effect on the default method is displayed If needed change your methods to accommodate the new hardware Advanced User Guide 25 3 Configuration Oven 26 See Unconfigured on page 25 and Ignore Ready on page 24 Maximum temperature Sets an upper limit to the oven temperature Used to prevent accidental damage to columns The range is 70 to 425 C Equilibrationtime The time after the oven approaches its setpoint before the oven is
11. the lower the pulse frequency required to match the reference current When a component that captures electrons passes through the cell the pulse rate rises This pulse rate is converted to a voltage and recorded uECD safety and regulatory information 154 The Ni isotope The radioactive isotope used in the cell is Ni It is plated onto the inner surface of the cell body and is solid at temperatures used in chromatography Some other properties are listed below Table 24 Properties of 63Ni Property Value Half life 101 1 years Emission 65 87 keV max beta radiation Melting point 1453 C Dimensions of the active part of the Inside diameter 6 mm uECD Height 4 2 mm Total activity uECD cell 555 MBq 15 millicuries maximum Advanced User Guide uECD warnings Detectors 10 uECD licenses Customers in the United states can purchase an exempt model uECD Customers outside the United States should contact their local Agilent sales office for information Although beta particles at this energy level have little penetrating power the surface layer of the skin or a few sheets of paper will stop most of them they may be hazardous if the isotope is ingested or inhaled For this reason the cell must be handled with care Radioactive leak tests must be performed at the required intervals not applicable to exempt models the inlet and outlet fittings must be capped when the detector is not in use corros
12. through a hydrogen air flame The hydrogen air flame alone creates few ions but burning an organic compound increases the number of ions produced A polarizing voltage attracts these ions to a collector located near the flame The current produced is proportional to the amount of sample being burned This current is sensed by an electrometer converted to digital form and sent to an output device The FID uses three supply gases hydrogen makeup gas and air and two supply lines Air flows through one supply line while hydrogen mixed with the makeup gas flows through the other All three supply gases use e A filter frit to protect the flow path and limit the flow rate e A proportional valve to control the pressure e A pressure sensor and restrictor to control the valve The hydrogen and makeup mix outside the flow module and enter the detector at the base of the jet Air enters above the jet 141 10 Detectors j PS Pressure Sensor Column How FID units are displayed in Agilent data systems and on the GC The GC displays the FID signal in picoamperes pA The following table lists how different data systems convert the display units to reporting units Table 21 Unit conversions Data system Height units LSV height units Area units Noise ASTM Agilent data system 1pA 1 3 x104 pA 1 pA sec 0 038 pA SIGRange 0 1x 10 pA 1 3x 107 pA 1x 104 pA 0 038 pA SIGRange 5 3 2x 10 pA 4 2 x 10 pA 3 2x 10 pA 0 038 pA
13. Analog ivi 1 25 x 107 pA device dependent 1 25 x 107 pA 0 038 pA Noise is recommended maximum when determining MDL t SIGRange used with 3393 and 3396 integrators Analog 1V is an approximate value 142 Advanced User Guide Detectors 10 To light the FID flame Press Front Det or Back Det scroll to Flame then press On Yes To extinguish the FID flame Press Front Det or Back Det scroll to Flame then press Off No FID automatic reignition Lit offset Lit offset is the expected minimum difference between the FID output with the flame lit and the output with the flame off The GC checks this value during runs and when loading a method During a run if the output falls below the Lit offset value the FID will attempt to reignite three times If after the third attempt the output does not increase by at least this value the detector shuts down all functions except temperature and makeup gas flow When loading a method that includes a Flame On setting the GC performs a similar check If the detector output is less than the Lit offset it will attempt reignition after reaching method setpoints The default setting for Lit offset is 2 0 picoamps This is a good working value for all but very clean gases and systems You may want to lower this setpoint if the detector attempts to reignite when the flame is still on thus producing a shutdown To change Lit offset 1 Press Config Front Det or Confi
14. Column Inlet Retest 15 After the inlet passes the test restore the GC to operating condition Remove any caps plugs Reinstall the column Restore the correct column configuration Load the operating method 102 Advanced User Guide Checking for Leaks 7 To Correct Leaks in the Packed Column Inlet Advanced User Guide If the inlet fails a pressure decay test check the following Check the caps plugs used in the test make sure each is correctly installed and tight If you performed the leak test after performing maintenance check for proper installation of the part s handled during the maintenance Check the tightness of the septum nut See To change the septum on the purged packed inlet Check the septum Replace if old or damaged Check that the top insert weldment is installed tightly Replace the O ring See To change the O ring on the purged packed inlet Also check the glass insert See To change the glass insert on a PP inlet Replace the ferrule seal on the adapter Make sure the inlet temperature remained constant during the test If these items do not resolve the problem contact Agilent for service 103 7 Checking for Leaks 104 Advanced User Guide Agilent 7820A Gas Chromatograph Advanced User Guide Inlets Using Hydrogen 106 Inlet Overview 107 Carrier Gas Flow Rates 108 About Gas Saver 109 Pre Run and Prep Run 110 Auto Prep Run 111 About Heaters 112 About the S
15. Enter the rate Rate 2 at which you want the oven temperature to increase for the second oven ramp Enter the final temperature Final temperature 2 Enter the number of minutes Final time 2 that you want the oven to hold the final temperature To end the temperature program after the second ramp set Rate 3 to zero To add additional oven ramps repeat the steps described Advanced User Guide About Columns Columns and Oven 9 In all GCs a sample which is a mixture of several components is vaporized in an inlet separated in a column and examined in a detector The column separates components in time because e When a vaporized component is presented with a gas phase and a coating phase it divides between the two phases according to its relative attraction to the two phases e The attraction can be solubility volatility polarity specific chemical interaction or any other property that differs from one component to another e If one phase is stationary the coating and the other is moving the carrier gas the component will travel at a speed less than that of the moving phase How much less depends on the strength of the attraction e If different components have different attractions they will separate in time Selecting the correct packed glass column type This topic is covered in the Maintenance manual See To attach a packed column to the purged packed inlet for details About th
16. GC configuration press Options select Keyboard amp Display and press Enter Scroll down to Hard Configuration Lock and press Off No 2 Press Config and scroll to Thermal Aux 1 3 With Unconfigured selected press Mode Type and select Install Heater A1 if the heated device is plugged into the valve box bracket plug labeled A1 4 Press Enter after making selection 5 When prompted by the GC turn the power off then on again To configure a MSD transfer line heater 1 Check that a power source for the MSD heater was assigned See To assign a GC power source to an Aux thermal zone on page 35 2 Press Config and scroll to Thermal Aux 1 or Back inlet depending on where the MSD heater was assigned and press Enter For a single channel GC select Back inlet For a dual channel GC select Thermal Aux 1 3 Scroll to Auxiliary type press Mode Type scroll to and select the MSD transfer line and press Enter To configure a nickel catalyst heater 1 Check that a power source for the Nickel Catalyst heater was assigned See To assign a GC power source to an Aux thermal zone on page 35 2 Press Config and scroll to Back inlet and press Enter Advanced User Guide 35 3 Configuration 3 Scroll to Auxiliary type press Mode Type scroll to and select Nickel catalyst and press Enter 36 Advanced User Guide PCM A PCM B Configuration See Unconfigured on page 25 and Igno
17. O ring and replace it if it is hard and brittle or cracked See To change the O ring on the purged packed inlet If unsure of the quality of the adapter ferrule replace it See To change the glass insert on a PP inlet Set the inlet temperature to 150 C Allow the inlet temperature to stabilize Temperature changes can invalidate the test Cap the septum purge fitting with the ECD TCD detector plug Advanced User Guide Checking for Leaks 7 Back inlet purge vent Back inlet split vent Front inlet split vent Front inlet purge vent lt Front purge vent shown plugged pres 11 Monitor the inlet pressure It should rise When the pressure rises above 25 psi 172 kPa turn off the carrier flow Press Front Inlet or Back Inlet Scroll to Total flow and press Off No If pressure cannot be achieved there is either a large leak or the supply pressure is too low 12 Quickly turn off the carrier gas supply at its source 13 Let the pressure stabilize for approximately 10 seconds The pressure should be between 25 and 28 psi 172 and 193 kPa 14 Monitor the pressure for 5 minutes Use the timer by pressing Time and Enter Advanced User Guide 101 7 Checking for Leaks A pressure drop of less than 0 25 psig 0 05 psi min or less 1 72 kPa or 0 34 kPa min is acceptable If the pressure drops much faster than the acceptable rate see To Correct Leaks in the Packed
18. To determine sequence status Press Seq Control to display the current status of the active sequence There are six possible sequence status modes To start a sequence Start running Ready wait Paused resume Stopped Aborted No sequence Press Seq Control scroll to Start sequence and press Enter The sequence status will change to Running The sequence continues to run until all subsequences are executed or until one of the events described under To abort a sequence on page 87 occurs Advanced User Guide Methods and Sequences 6 Ready wait If a sequence is started but the instrument is not ready due to oven temperature equilibration times etc the sequence will not start until all instrument setpoints are ready To pause and resume a sequence Press Seq Control scroll to Pause sequence and press Enter The sequence status changes to paused and you are given the option to resume or stop the paused sequence The sequence halts when the current sample run is complete To continue the paused sequence scroll to Resume sequence and press Enter When a sequence is resumed it starts with the next sample To stop a sequence A sequence automatically stops at the end of the last active subsequence unless Repeat sequence is On in the Post Sequence events To stop a running sequence scroll to Stop sequence and press Enter A stopped sequence can only be restarted from the beginning To abor
19. When you enter a value here or press On Yes to use the stored value detector gas flows turn on the bead heats and the bead voltage adjusts until Output is stable and equal to the entered value There are five stages of Adjust offset Detector off When the detector is off Adjust offset and Bead voltage are Off and initial Output is displayed Detector on detector temperature less than 150 C When you enter an Adjust offset value or press On detector gases turn on and the display blinks the Temp not ready message Detector on waiting for oven and or detector to reach temperature setpoint and equilibrium If the oven or detector is not at setpoint the display continues to blink the Temp not ready message Detector on Dry Bead On If Dry Bead is On the temperature rise holds at 150 C for 5 minutes to remove moisture then continues to the setpoint 167 10 Detectors 168 Detector on during adjust offset When the detector and oven temperatures reach setpoint and equilibrate the Adjust offset process begins The bead voltage is slowly increased until the output is close to the Adjust offset value The display blinks Detector Slewing Detector on and ready When the Adjust offset value is reached the Adjust offset line reads Done and displays the offset target setpoint Your detector is on and ready The display shows the actual Bead voltage Setting NPD adjust offset on the clock table You can use the Clo
20. a jet with a wider tip id e When using packed columns in high column bleed applications the jet tends to clog with silicon dioxide For capillary optimized fittings select one of the following from Table 28 Table 28 Jets for capillary optimized fittings Figure3ID Jet type Part number Jet tip id Length 1 Capillary with extended jet G1534 80580 0 29 mm 0 011 inch 51 5 mm recommended 2 Capillary G1531 80560 0 29 mm 0 011 inch 43mm 3 High temperature G1531 80620 0 47 mm 0 018 inch 43mm 51 5 mm 1 n 43 mm ea og amp 43 mm 3 ities 1 2 3 Figure 2 Capillary optimized NPD jets For the adjustable NPD select one of the following from Table 29 Advanced User Guide 165 10 Detectors Table 29 Jets for adaptable fittings Figure 4 ID Jet type Part number Jet tip id Length 1 Capillary with extended jet 1534 80590 0 29 mm 0 11 inch 70 5 mm recommended 2 Capillary 19244 80560 0 29 mm 0 011 inch 61 5 mm 3 Capillary high temperature 19244 80620 0 47 mm 0 018 inch 61 5 mm 4 Packed 18710 20119 0 46 mm 0 018 inch 63 6 mm 70 5 mm a 1 i 61 5 mm 2 LD 61 5 mm eo 63 6 mm See Figure 3 Adaptable NPD jets To configure the NPD wet 166 In addition to the Ignore Ready and Makeup gas type the NPD requires the following configuration settings Scroll to each and enable disable using On Yes or Off No Auto Adjust Bead Recommended On When On the automatic adjust offset process starts
21. action is desired See From the run or clock time tables on page 183 Using run time events 14 The Run Table key is used to program the following timed events e Valves 1 2 e Analog signal definition zero and range e TCD negative polarity on off e Detector gas flow on off including NPD Hs fuel gas Advanced User Guide Programming 2 Programming run time events The run table Aa WwW N Press Run Table Press Mode Type to see the available run time events Scroll to the event to be programmed Press Enter Enter values for the Time and the other parameter Press Enter after each entry Press Mode Type to add another event Press Status to terminate entries The programmed events are arranged in order of execution time in the Run Table This is a brief example RUN TABLE 1of3 Event 1 rotates a valve Time 0 10 Valve 2 On RUN TABLE 2 of 3 Event 2 adjusts the signal Time 3 range Analog signal 2 range 2 RUN TABLE 3 of 3 Event 3 resets Valve 2 to its Time 4 20 original position in preparation Valve 2 Off for another run Valves do not reset automatically Adding events to the run table 1 To add new events to the run table press Mode Type while on the Time line of any entry Select the event type Set appropriate Time and other parameters Some require numbers others require On Yes or Off No Repeat until all entries are added Events are aut
22. change in the GC display but you will see the change in the online plot available in the data system To change this setting press Config scroll to Instrument then scroll to Zero Init Data Files Advanced User Guide 203 13 GC Output Signals 204 Advanced User Guide Agilent 7820A Gas Chromatograph Advanced User Guide 14 Miscellaneous Topics About Pressure Control 206 Pressure units 206 To Use the Stopwatch 207 Service Mode 208 Service Reminders 208 Other functions 208 a Agilent Technologies 205 14 Miscellaneous Topics About Pressure Control Pressure units There are two common ways of expressing gas pressures psia Absolute pressure measured relative to vacuum psig Gauge pressure measured relative to atmospheric pressure This name is used because most pressure gauges have one side of the sensing element exposed to the atmosphere The two measurements are related by psia psig atmospheric pressure 206 Advanced User Guide To Use the Stopwatch Advanced User Guide Miscellaneous Topics 14 In the stopwatch mode both the time to 0 1 second and reciprocal time to 0 01 min 1 are displayed The stopwatch is useful when measuring flows with a bubble flowmeter 1 2 3 4 Press Time and scroll to the time line Press Enter to start the stopwatch Press Enter again to stop Press Clear to set to zero You can access other functions while the stopwatch is running Pre
23. declared Ready The range is 0 to 999 99 minutes Used to ensure that the oven contents have stabilized before starting another run To configure the oven 1 Press Config Oven 2 Scroll to Maximum temperature Enter a value and press Enter 3 Scroll to Equilibration time Enter a value and press Enter Advanced User Guide Configuration Front Inlet Back Inlet See Unconfigured on page 25 and Ignore Ready on page 24 To configure the Gas type The GC needs to know what carrier gas is being used 1 Press Config Front Inlet or Config Back Inlet 2 Scroll to Gas type and press Mode Type 3 Scroll to the gas you will use Press Enter This completes carrier gas configuration Advanced User Guide 3 27 3 Configuration Column Length The length in meters of a capillary column Enter 0 for a packed column or if the length is not known Diameter The inside diameter in millimeters of a capillary column Enter 0 for a packed column Film thickness The thickness in millimeters of the stationary phase for capillary columns Inlet Identifies the source of gas for the column Outlet Identifies the device into which the column effluent flows Thermal zone Identifies the device that controls the temperature of the column To configure a single column 28 You define a capillary column by entering its length diameter and film thickness You then enter the device controlling the
24. gas sampling valves installed To column Carrier in LOAD position INJECT position Loop Sample in Sample out qa Load position The loop is flushed with a stream of the sample gas The column is flushed with carrier gas Advanced User Guide 183 11 Valves 184 Inject position The filled loop is inserted into the carrier gas stream The sample is flushed onto the column The run starts automatically Carrier gas may be provided by an optional PCM channel To do this configure the column and specify the PCM channel as the inlet The channel then becomes programmable with four operating modes Sampling valves have two positions Load position The loop external for gas sampling internal for liquid sampling is flushed with a stream of the sample The column is flushed with carrier gas Inject position The filled loop is inserted into the carrier gas stream The sample is flushed onto the column The run starts automatically The sampling valve control parameters are Loadtime Time in minutes that the valve remains in the Load position before becoming ready Injecttime Time in minutes that the valve remains in the Inject position before returning to the Load position The sampling valve cycle is 1 The sampling valve rotates to the Load position Load time begins Valve is not ready 2 Loadtime ends The valve becomes ready 3 If everything else is ready the GC becomes ready If anything is not ready
25. gases are connected a column is properly installed and the system is free of leaks Set the oven temperature and the inlet temperature and flow Make sure your carrier gas type is the same as that plumbed to your GC 1 Press Front Det or Back Det 2 Set the detector temperature To keep the uECD cell clean this temperature must be higher than the oven temperature 3 Verify that the makeup gas type is the same as that plumbed to your instrument The gas type is in parentheses next to the Makeup line on the parameter list Change the gas type if necessary 4 Enter a value for the makeup gas flow If you are using packed columns turn off the makeup gas If your capillary column is defined choose a flow mode and set the makeup or combined gas flow If your capillary column is not defined only constant makeup flow is available Enter a makeup gas flow 159 10 Detectors About the NPD We strongly recommend that you allow the firmware to perform Auto Adjust and set the Bead Voltage NPD flows and general information The NPD passes sample and carrier through a hydrogen air plasma A heated ceramic or glass source called the bead is just above the jet The low hydrogen air ratio cannot sustain a flame minimizing hydrocarbon ionization while the alkali ions on the bead surface facilitate ionization of nitrogen or phosphorus organic compounds The output current is proportional to the number of ions collected I
26. last through thousands of injections 208 Other functions These are for use by trained Agilent personnel They are described in the Service Manual Advanced User Guide
27. measured in terms of bandwidth Your recorder or integrator should have a bandwidth twice that of the signal you are measuring The GC allows you to operate at two speeds The faster speed allows minimum peak widths of 0 004 minutes 8 Hz bandwidth while the standard speed allows minimum peak widths of 0 01 minutes 1 6 Hz bandwidth If you use the fast peaks feature your integrator should operate at around 15 Hz Advanced User Guide GC Output Signals 13 Selecting fast peaks analog output Advanced User Guide 1 Press Config Analog Out 2 Scroll to Fast peaks and press On Agilent does not recommend using Fast peaks with a thermal conductivity detector Since the gas streams switch at 5 Hz the gain in peak width is offset by increased noise 199 13 GC Output Signals Digital Signals 200 Digital zero The GC outputs digital signals only to an Agilent data system The following discussions describe features that impact the data sent to data systems not the analog data available to integrators Access these features from the data system These features are not accessible from the GC keypad Available only from an Agilent data system Digital signal outputs respond to a zero command by subtracting the signal level at the time of the command from all future values Signal Freeze and Resume Available only from an Agilent data system Some run time operations such as changing signal assignments or s
28. or flow and a Final time The program ends when it reaches a Rate that is set to 0 Off 135 136 Columns and Oven When a flow or pressure program is running the Pressure Flow and Velocity lines that you used to set constant conditions show the progress of the program The oven program determines the length of the run If a flow or pressure program ends before the analytical run does the flow or pressure remains at the last final value Programming column pressure or flow 1 2 Press Col then enter the column number Scroll to Initial pressure or Initial flow Type the desired value and press Enter Similarly enter a value for Initialtime This completes the initial part of the program To begin a ramp enter a positive value for Rate 1 It does not matter whether you are programming up or down the rate is always positive If Rate 1 is zero the program ends here If you enter any other value the Final value lines for the first ramp appear and the cursor moves to the line Enter values for Final pressure 1 or Final flow 1 and Final time 1 This completes the first ramp To enter a second ramp scroll to the appropriate Rate line and repeat steps 5 and 6 A maximum of 3 ramps can be entered Advanced User Guide Nickel Catalyst Tube Columns and Oven About the nickel catalyst tube Carrier gas The Nickel Catalyst Tube accessory G4337A is used for trace analysis of CO and CO wi
29. sensors in all modules 47 Column calibration 47 Communication 51 Configuring the IP address forthe GC 51 Keyboard and Display 52 Advanced User Guide 5 Chromatographic Checkout About Chromatographic Checkout 54 To Prepare for Chromatographic Checkout 55 To Check FID Performance 56 To Check TCD Performance 60 To Check NPD Performance 64 To Check uECD Performance 68 To Check FPD Performance Sample 5188 5953 72 6 Methods and Sequences Creating Methods 80 To program a method 80 To program the ALS 81 To save a method 81 To load a stored method 81 Method mismatch 81 Creating Sequences 83 About the priority sequence 83 To program a sequence 83 To program a priority sequence 84 To program an ALS subsequence 85 To program a valve subsequence 85 To program post sequence events 85 To save a sequence 86 To load a stored sequence 86 To determine sequence status 86 To start a sequence 86 To pause and resume a sequence 87 To stop a sequence 87 To abort a sequence 87 7 Checking for Leaks Preparing the GC for Maintenance 90 Column and oven preparation 90 Inlet preparation 90 Detector preparation 90 Leak Check Tips 91 To Check for External Leaks 92 To Check for GC Leaks 93 Advanced User Guide To Perform a SS Inlet Pressure Decay Test 94 To Correct Leaks in the Split Splitless Inlet 98 To Perform a PP Inlet Pressure Decay Test 99 To Correct Leaks in the Packed Column Inlet 103 8 Inlets Using Hydrogen 106 Inlet Overv
30. tS 101150234 5 Agilent 7820A Gas Chromatograph Advanced User Guide ope Agilent Technologies Notices Agilent Technologies Inc 2009 2011 No part of this manual may be reproduced in any form or by any means including electronic storage and retrieval or transla tion into a foreign language without prior agreement and written consent from Agilent Technologies Inc as governed by United States and international copyright laws Manual Part Number 64350 90020 Edition Third edition June 2011 Second edition January 2010 First edition March 2009 Printed in China Agilent Technologies Inc 412 Ying Lun Road Waigoagqiao Freed Trade Zone Shanghai 200131 P R China Technology Licenses The hardware and or software described in this document are furnished under a license and may be used or copied only in accordance with the terms of such license Restricted Rights If software is for use in the performance of a U S Government prime contract or sub contract Software is delivered and licensed as Commercial computer soft ware as defined in DFAR 252 227 7014 June 1995 or as a commercial item as defined in FAR 2 101 a or as Restricted computer software as defined in FAR 52 227 19 June 1987 or any equivalent agency regulation or contract clause Use duplication or disclosure of Software is subject to Agilent Technologies standard commercial license terms and non DOD Departments a
31. the duckbill seal used Split Splitless inlet split mode overview During a split injection a liquid sample is introduced into a hot inlet where it vaporizes rapidly A small amount of the vapor enters the column while the major portion exits from the split purge vent The ratio of column flow to split vent flow is controlled by the user Split injections are primarily used for high concentration samples when you can afford to lose most of the sample out the split purge vent It is also used for samples that cannot be diluted 114 Advanced User Guide Inlets 8 The split ratio is equal to the split vent flow divided by the column flow If the column has been configured the desired split ratio can be entered directly The pneumatics for this inlet in split mode operation are shown in the figure below Split Carrier Supply Septum Purge 80 PSI EPC Module Split Vent Trap Inlet Weldment FS Flow Sensor PS Pressure Sensor Column Split Splitless inlet splitless mode overview In this mode the split vent valve is closed during the injection and remains so while the sample is vaporized in the liner and transferred to the column At a specified time after injection the valve opens to sweep any vapors remaining in the liner out the split vent This avoids solvent tailing due to the large inlet volume and small column flow rate Specify the purge time and purge flow rate in the inlet parameter list Advanced User Gu
32. you are using an Agilent automatic sampling system the Prep Run function is automatic Start the sampler It generates the Prep Run function When all the setpoints are reached and the GC becomes Ready sample injection begins Advanced User Guide Inlets 8 Auto Prep Run To set this parameter usually for a non Agilent integrator workstation or other controlling device 1 Press Config to view a list of configurable parameters 2 Scroll to Instrument and press Enter 3 Scroll to Auto prep run and press On Yes Advanced User Guide 111 8 inlets About Heaters Near top right corner of front detector board Near top right corner of back detector board End of valve bracket 112 Inlets and detectors valve boxes etc are heated There are six heater connectors on the GC mainframe located as shown here Front of GC 3 1 Near front inlet 2 Near back inlet All heater connectors are square 4 conductor receptacles mounted on brackets The next table describes the heater locations that are available for each module Table 12 Heater connection locations by module Module Available heater connection location Front inlet 1 or None Back inlet 2 or None Front detector 3 Back detector 4 PCM A 5or6or1or2 PCM B 5or6or1or2 PCM C 5or6or1or2 AUX 1 2 3 None AUX 4 5 6 None AUX 7 8 9 None Valve box 5 Advanced User Guide
33. you to interrupt a running sequence without having to edit it If Use priority is On then 1 The GC and ALS complete the current run then the sequence pauses 2 The GC runs the priority sequence 3 The GC resets the Use priority parameter to Off 4 The main sequence resumes where it paused To program a sequence Advanced User Guide 1 Press Seq Press again if necessary to display subsequence information 2 Create a priority sequence if desired See To program a priority sequence on page 84 If you might want to use 83 6 Methods and Sequences a priority sequence you must program it now Once the sequence starts you cannot edit it without stopping it Scroll to the Method line of Subseq1 and enter a method number Use 0 for the currently active method 1 to 9 for the stored methods or Off No to end the sequence Press Mode Type to select a valve or injector type See To program a valve subsequence on page 85 or To program an ALS subsequence on page 85 Create the next subsequence or scroll to Post Sequence See To program post sequence events on page 85 Save the completed sequence See To save a sequence on page 86 To program a priority sequence 1 Press Seq Press again if necessary to display subsequence information Scroll to Priority Method and enter a method number Use 0 for the currently active method 1 to 9 for the stored methods
34. 50 C Wrong flows set for installed filter Advanced User Guide Chromatographic Checkout 5 If the baseline output is zero verify the electrometer is on and the flame is lit 17 If using a data system prepare the data system to perform one run using the loaded checkout method Make sure that the data system will output a chromatogram 18 Start the run If performing an injection using an autosampler start the run using the data system or press Start on the GC If performing a manual injection with or without a data system a Press Prep Run to prepare the inlet for splitless injection b When the GC becomes ready inject 1 uL of the checkout sample and press Start on the GC 19 The following chromatogram shows typical results for a new detector with new consumable parts installed FPD1 A 65_S1 SIG10011 D i FPD2B 65_S1 SIG10011 D 150 pA 4 J Methylparathion 99429912 30004 25004 20004 in 10004 Isooctane 04 N N Advanced User Guide 77 5 Chromatographic Checkout 78 Advanced User Guide Agilent 7820A Gas Chromatograph Advanced User Guide 6 Methods and Sequences Creating Methods 80 To programamethod 80 To program the ALS 81 To save a method 81 To load a stored method 81 Method mismatch 81 Creating Sequences 83 About the priority sequence 83 To program a sequence 83 To program a priority sequence 84 To program an ALS subsequence 85 T
35. For network LAN operation the GC needs an IP address It can get this from a DHCP server or it can be entered directly from the keyboard In either case see your LAN administrator To use a DHCP server 1 Press Options Scroll to Communications and press Enter 2 Scroll to Enable DHCP and press On Yes When prompted turn the GC off and then on again To set the LAN address at the keyboard 1 Press Options Scroll to Communications and press Enter 2 Scroll to Enable DHCP and if necessary press Off No Scroll to Reboot GC Press On Yes and 0n Yes 3 Press Options Scroll to Communications and press Enter 4 Scroll to IP Enter the numbers of the GC IP address separated by dots and press Enter A message tells you to power cycle the instrument Do not power cycle yet Press Clear 5 Scroll to GW Enter the Gateway number and press Enter A message tells you to power cycle the instrument Do not power cycle yet Press Clear 6 Scroll to SM and press Mode Type Scroll to the appropriate subnet mask from the list given and press Enter A message tells you to power cycle the instrument Do not power cycle yet Press Clear 7 Scroll to Reboot GC Press On Yes and On Yes to power cycle the instrument and apply the LAN setpoints Advanced User Guide 51 4 Options Keyboard and Display 52 Press Options and scroll to Keyboard and Display Press Mode Type The following param
36. For thermally labile or reactive samples use G1544 80700 open top or G1544 80730 top taper liners Liner Description Volume Mode Deactivated Part Number Single Taper Glass 900 uL Splitless Yes 5062 3587 Wool Single Taper 900 uL Splitless Yes 5181 3316 _ Dual Taper 800 uL Splitless Yes 5181 3315 E 2 mm Quartz 250 uL Splitless No 18740 80220 E 2 mm Quartz 250 uL Splitless Yes 5181 8818 1 5 mm 140 uL Direct No 18740 80200 S Inject Purge 3 and Trap Headspace _ 7 Single Taper Glass 900 uL Splitless Yes 5062 3587 Wool _ Single Taper 900 uL Splitless Yes 5181 3316 a 4mm Single Taper Direct column connect Yes G1544 80730 gt 4 mm Dual Taper Direct column connect Yes G1544 80700 Advanced User Guide 119 120 Inlets Vapor Volume Calculator Agilent provides a Vapor Volume Calculator to help you determine if a liner is suitable for a method To use the calculator install the Agilent Instrument utility provided with the GC The calculator is also provided with the Agilent Instrument Utilities software Setting parameters for the S SL split mode Mode The current operating mode split Temperature Actual and setpoint inlet temperatures Pressure Actual and setpoint inlet pressure Split ratio The ratio of split vent flow to column flow Column flow is set at the Column parameter list This line appears only if your columns in the flow path are defined Split flow Flow in mL min from the split vent T
37. Freeze and Resume 200 Data rates with Agilent data systems 201 Zero Init Data Files 203 14 Miscellaneous Topics Advanced User Guide About Pressure Control 206 Pressure units 206 To Use the Stopwatch 207 Service Mode 208 Service Reminders 208 Other functions 208 10 Advanced User Guide Agilent 7820A Gas Chromatograph Advanced User Guide e Software Keypad Ee Agilent Technologies 11 1 Software Keypad Using the Software Keypad The Agilent software keypad remote controller software provides the ability to program and use the 7820A Gas Chromatograph GC Refer to the Operating Guide for instructions for its installation and use Connected to 192 168 0 26 Connection C Setting 5 Help H Not Ready Run Pre Run Remote RunLlog Gas Saver Service Due J J J J J amp Prep Run Der Our Mode Clear 1 2 5 8 abe te w El lt n rmm rnrn n Seq Control wo SS es Es O O Load Method Store 7 E Connected to 192 168 0 26 Figure 1 Software keypad remote controller All instructions in this manual assume the use of the software keypad unless otherwise noted 12 Advanced User Guide Agilent 7820A Gas Chromatograph Advanced User Guide 2 Programming Run Time Programming 14 Using runtime events 14 Programming runtime events 15 The run table 15 Adding events to the run table 15
38. If you are using Clock Table or sequence control the GC waits until everything is ready then executes the valve inject command If you are not using Clock Table or sequence control the valve injection can be made at any time from the keyboard 4 The sampling valve rotates keyboard command or sequence control to the Inject position Inject time begins The run begins 5 Injecttime ends Return to step 1 Advanced User Guide Agilent 7820A Gas Chromatograph Advanced User Guide 12 Cables About Cables and Back Panel Connectors 186 Back panel connectors 186 Sampler connectors 186 Signal connector 186 REMOTE connector 187 TEST PORT connector 187 LAN connector 187 Using the Remote Start Stop cable 188 Cable Diagrams 193 Analog cable general use 193 Remote start stop cable 193 Ee Agilent Technologies 185 12 Cables About Cables and Back Panel Connectors Some parts of an analysis system are connected to the GC by cables These cables and the back panel connectors to which they connect are described in this section Back panel connectors These are the connectors on the back panel of the GC SIGNAL REMOTE LAN ALS Port Back ALS Port Front TEST PORT Sampler connectors If using an ALS connect to the GC using the following connectors ALS PORT Front An injector typically mounted over the front inlet ALS PORT Back An inje
39. Packed n a Any All Large capillary n a Any OK if resolution All not critical Advanced User Guide 107 8 inlets Carrier Gas Flow Rates 108 The flow rates in Table 11 are recommended for all column temperatures Table 11 Column size and carrier flow rate Columntype Column size Carrier flow rate mL min Hydrogen Helium Nitrogen Packed 1 8 inch 30 20 1 4 inch 60 40 Capillary 0 05 mm id 0 5 0 4 n a 0 10 mm id 1 0 0 8 n a 0 20 mm id 2 0 1 6 0 25 0 25 mm id 2 5 2 0 0 5 0 32 mm id 3 2 2 6 0 75 0 53 mm id 5 3 4 2 1 5 Advanced User Guide About Gas Saver Split mode Split vent flow mL min Splitless mode Split vent flow mL min 50 40 30 20 Inlets Gas saver reduces carrier flow from the split vent after the sample is on the column It applies to the Split Splitless inlet all modes It is most useful in split applications Column head pressure and flow rate are maintained while purge and split vent flows decrease Flows except column flow remain at the reduced level until you press Prep Run Start Gas saver time 3 min Prep Run Regular flow SS 4 Run ends I A I I I 1 1 Gas saver flow 1 Gas saver flow ie ee fee Ge af ee i if oo 50 40 30 20 10 To use gas saver Advanced User Guide 2 3 4 5 6 7 8 Time min Start Gas saver time 5 min Purge time 2 min Run ends Purge flow Gas saver flow Time min Press
40. Source gas pressures Choose a flow find a pressure and set source pressure 10 psi 70 kPa higher 161 10 Detectors 150 7 Z J hi 100 a Pag 2 Flow mL min I x Helium ae 50 LZ ae me en a ete F in pape Pressure psig 1 2 30 40 50 60 70 kPa 69 138 207 276 345 414 483 5 4 Hydrogen 3 Flow mL min 2 1 Pressure psig 4 8 12 16 20 kPa 28 55 83 110 138 Temperature programming The NPD is flow sensitive If you are using temperature programming in which the column flow resistance changes with temperature set up the instrument as follows e Set the carrier gas in the Constantflow mode Set detector makeup gas to Constant makeup e If you choose to work in the constant pressure mode the makeup gas should be set in the Column makeup constant mode NPD required gas purity Because of its high sensitivity the NPD requires very pure at least 99 9995 gases We strongly recommend that moisture and organics traps be used on the carrier gas and 162 Advanced User Guide Detectors 10 all detector gases including the detector hydrogen air and makeup gases Do not use plastic including PTFE tubing plastic bodied traps or O ring seals Setting parameters for the NPD Before operating the NPD make sure that detector gases are connected a column is installed and the system is free of leaks Set the oven temperature inl
41. TCD 146 About the uECD 154 About the NPD 160 About the FPD 171 Ee Agilent Technologies 139 10 Detectors About Makeup Gas 140 Most detectors use a makeup gas to increase the flow rate through the detector body This sweeps peaks out of the detector quickly avoiding mixing of components and loss of resolution This is particularly important with capillary columns because the column flow rates are so small The makeup gas line of your detector parameter list changes depending on your instrument configuration If you have an inlet with the column not defined the makeup flow is constant If you are operating with column defined you have a choice of two makeup gas modes Constant makeup This mode provides a constant flow of makeup gas to the detector Column makeup constant This mode provides a variable flow of makeup gas to the detector As column flow increases or decreases the makeup flow changes to provide a constant combined flow to the detector If you choose this option enter a value under Combined flow The Combined flow line always displays the same value while the Makeup line changes as the actual makeup flow changes To change the makeup gas flow mode 1 Press Front Det or Back Det 2 Scroll to Mode Press Mode Type 3 Scroll to the correct mode and press Enter Advanced User Guide About the FID Advanced User Guide Detectors 10 The FID passes sample and carrier gas from the column
42. a column is installed or the FPD fitting is plugged before turning on the air or hydrogen An explosion may occur if air and hydrogen are allowed to leak into the oven Advanced User Guide 1 Press Front det or Back det 2 Set the detector temperature It must be greater than 120 C for the flame to light 3 Change the hydrogen flow rate if desired Press Off No 4 Change the air flow rate if desired Press Off No 5 If you are using packed columns turn off the makeup gas and proceed to step 7 6 If you are using capillary columns a Verify that makeup gas type is the same as that plumbed to your instrument next to Makeup in the parameter list Change the gas type if necessary b If your capillary column is defined choose a flow mode and set the makeup gas flow or combined flow c If your capillary column is not defined enter a makeup gas flow Only constant flow is available 7 Scroll to Flame and press On Yes This turns on the air and hydrogen and initiates the ignition sequence On ignition the signal increases Typical levels are 4 to 40 pA in sulfur mode 10 to 70 pA in phosphorus mode Verify that the flame is lit by holding a cold shiny 175 10 Detectors surface such as a mirror or chrome plated wrench over the vent exit Steady condensation indicates that the flame is lit 176 Advanced User Guide Agilent 7820A Gas Chromatograph Advanced User Guide 11 Valves The Valve Box 178
43. able 33 for cabling requirements for other configurations Table 33 Cabling requirements 7820A GC connected to Required Cable s Part number 7693A Automatic Liquid Injector cable G4514 60610 Sampler 7697A Headspace Remote 9 pin G1530 60930 Sampler male 6 pin connector 3395B 3396C Integrator Remote 9 pin 15 pin 03396 61010 Analog 2 m 6 pin G1530 60570 Non Agilent General purpose analog G1530 60560 Integrator signal cable 2m 6 pin 191 12 Cables 192 Table 33 Cabling requirements continued 7820A GC connected to Required Cable s Part number Non Agilent General use remote data system 9 pin male spade lugs various lengths LAN Cable networking CAT 5 25 feet Cable LAN crossover 35900 60670 2 m 35900 60920 5 m 35900 60930 0 5 m 8121 0940 5183 4648 Advanced User Guide Cables 12 Cable Diagrams Analog cable general use UNTO pe im iiim 1530 60560 a Connector 1 Connector 2 The pin assignments for the general use analog out cable are listed in Table 34 Table 34 Analog cable general use output connections Connector 1 Connector 2 wire color Signal 1 Brown or violet Not used 2 White 0 to 1 V 0 to 10 V 3 Red Not used 4 Black 1V 6 Blue 10 V Shell Orange Ground Remote start stop cable co E 35900 60670 Y X Connector 2 Connector 1 The pin assignments for t
44. ally reduce the flows to the sulfur values Some experimentation will be needed When either of the flame ignition methods in this section is used the FPD automatically performs this sequence 1 Turns all detector gases air hydrogen makeup off Carrier remains on Sets air flow to 200 mL min Turns the glow plug ignitor on Ramps the hydrogen flow from 10 to 70 mL min Resets the air flow to the air flow setpoint Resets the hydrogen flow to the hydrogen flow setpoint Turns the makeup gas on on oOo A F Ww N Compares the signal change with the Lit offset value If the change is greater than Lit offset declares the flame on lit If it is less declares the flame off not lit For this process to work there must be enough air pressure to the pneumatics module to provide 200 mL min flow We recommend a supply pressure of 90 psi Advanced User Guide Detectors 10 Manual ignition 1 Press Front Det or Back Det 2 Scroll to Flame Press On Yes The flame ignition sequence begins Automatic ignition If the FPD output with the flame on falls below the flame off output plus the Lit offset value this is interpreted as a flame out condition The FPD runs the flame ignition sequence to relight the flame If this fails it runs the sequence again If the second attempt also fails the detector shuts down all functions except temperature and makeup gas flow Setting parameters for the FPD Verify that
45. and flows Maximum source pressure must not exceed 100 psi Use the maximum source pressure to achieve maximum makeup flow rate Table 25 Starting values Gas Recommended flow range Carrier gas Packed columns 30 to 60 mL min nitrogen or argon methane Capillary columns 0 1 to 20 mL min hydrogen nitrogen or depending on diameter argon methane Capillary makeup 10 to 150 mL min nitrogen or argon methane 30 to 60 mL min typical Temperature 250 C to 400 C Detector temperature is typically set 25 C greater than the highest oven ramp temperature Advanced User Guide Detectors 10 uECD makeup gas notes If the carrier gas type is different from the makeup gas type the makeup gas flow rate must be at least three times the carrier gas flow rate uECD sensitivity can be increased by reducing the makeup gas flow rate uECD chromatographic speed for fast peaks can be increased by increasing the makeup gas flow rate uECD temperature programming The uECD is flow sensitive If you are using temperature programming in which the column flow resistance changes with temperature set up the instrument as follows e Set the carrier gas in the Constantflow mode Set detector makeup gas to Constant makeup e If you choose to work in the constant pressure mode the makeup gas should be set in the Column makeup constant mode Setting parameters for the uECD Advanced User Guide Verify that your detector
46. ation Suppose your standalone GC is equipped with a single FID You have created and saved methods that use this detector Now you remove the FID and install a TCD in its place When you try to load one of your stored methods you observe an error message saying that the method and the hardware do not match Advanced User Guide 81 6 82 Methods and Sequences The problem is that the actual hardware is no longer the same as the hardware configuration saved in the method The method cannot run because it does not know how to operate the recently added TCD On inspecting the method you find that the detector related parameters have all been reset to the default values Correcting a method mismatch on a standalone GC This problem can be avoided if you follow this procedure for any hardware change even including the simple replacement of a defective detector board 1 Before changing any hardware press Config hardware module where hardware module is the device you intend to replace Press Mode Type Select Remove module and press Enter The module is now Unconfigured Turn the GC off Make the hardware change that you intended in this example remove the FID and its flow module and replace them with the TCD and its module Turn the GC on Press Config hardware module Press Mode Type Select Install module and press Enter The GC will install the new hardware module which corrects the active me
47. bar or kPa Purge time The time after the beginning of the run when you want the purge valve to open This is the time in which the vaporized sample transfers from the liner to the column Purge flow The flow in mL min from the purge vent at Purge time You will not be able to specify this value if any column in the flow path is not defined Total flow The actual flow to the inlet during a Pre run Pre run light is on and not blinking and during a run before purge time You cannot enter a setpoint at these times At all other times Total flow will have both setpoint and actual values If all columns in the flow path are defined 1 Press Front Inlet or Back Inlet Scroll to Mode and press Mode Type Select Splitless Set the inlet temperature Enter a Purge time and a Purge flow a A Ww N If desired turn on Gas saver Make certain the time is set after the Purge time 6 Press Prep Run see Pre Run and Prep Run on page 110 before manually injecting a sample this is automatic for Agilent ALS If a column in the flow path is not defined 1 Press Front Inlet or Back Inlet Scroll to Mode and press Mode Type Select Splitless Set the inlet temperature gt WwW N Enter a Purge time Advanced User Guide Inlets 8 5 Set your Total flow greater than the sum of column flow plus the septum purge flow see Pre Run and Prep Run on page 110 to guarantee adequate column flow 6 Pre
48. be 137 Nickel catalyst gas flows 137 Setting temperatures for the nickel catalyst tube 138 About Makeup Gas 140 About the FID 141 How FID units are displayed in Agilent datasystems andontheGC 142 To light the FID flame 143 To extinguish the FID flame 143 FID automatic reignition Lit offset 143 Recommended starting conditions for new FID methods 143 Setting parameters for FID 144 About the TCD 146 TCD pneumatics 148 TCD carrier reference and makeup gas 148 TCD gas pressures 149 Selecting reference and makeup flows forthe TCD 150 Chemically active compounds reduce TCD filament life 150 Changing the TCD polarity duringarun 151 Detecting hydrogen with the TCD using helium carrier gas 151 Setting parameters forthe TCD 152 About the uECD 154 uECD safety and regulatory information 154 uECD warnings 155 Safety precautions when handling uECDs 156 uECD gas flows 157 uECD linearity 157 uECD detector gas 157 uECD temperature 158 uECD analog output 158 Recommended starting conditions for new uECD methods 158 uECD makeup gas notes 159 11 Valves uECD temperature programming 159 Setting parameters forthe uECD 159 About the NPD 160 NPD flows and general information 160 NPD flow temperature and bead recommendations 161 NPD required gas purity 162 Setting parameters forthe NPD 163 Selecting an NPD beadtype 164 Selecting an NPD jet 165 To configure the NPD 166 Automatically adjusting NPD bead voltage 167 Setting NPD adjust offse
49. be programmed for temperature decreases as well as increases Final time 2 Final temperature 2 Rate 2 Final time 1 Rate 3 0 Programming setpoints Temperature Starting temperature of a temperature programmed run When the program begins this value is copied into a temporary setpoint called Inittemp At the end of the run Temperature is reset to the value in Init temp and the oven returns to its starting temperature Initial time Time in minutes that the oven will stay at the starting temperature after a programmed run has begun Rate The rate in C min at which the oven will be heated or cooled Advanced User Guide Oven ramp rates Columns and Oven 9 Final temperature Temperature of the oven at the end of a heating or cooling rate Finaltime Time in minutes that the oven will be held at the final temperature of a temperature programmed rate Total length of a run is determined by its oven temperature program The maximum allowable time for a run is 999 99 minutes If the program is still running at that time the run terminates See also Post Run Programming The highest rate that you can achieve depends on many factors including the room temperature temperatures of the inlets and detectors the amount of material inside the oven columns valves etc and whether or not this is the first run of the day Table 18 lists typical oven ramp rates Table 18 Oven ramp rates Temperature
50. bed below requires removing the column and capping the inlet column fitting This test can cannot find the following types of leaks The test can find leaks at the The test cannot find leaks at the septum column fitting septum nut gas supply bulkhead fittings to the flow module liner O ring seal tubing and connections in a transfer line connected to the inlet gold seal washer and reducing nut internal leaks in an EPC module inlet body flow manifold split vent valve split vent tubing and trap septum purge tubing seals within the tubing between the inlet flow module and the inlet body 1 Gather the following see Consumables and parts for the split splitless inlet No hole ferrule 1 4 inch wrench Heat resistant gloves if the inlet is hot Column nut New septum O ring Advanced User Guide Advanced User Guide 10 11 12 13 Checking for Leaks 7 ECD TCD Detector plug part no 5060 9055 Load the inlet maintenance method and wait for the GC to become ready Remove the column if installed Plug the column fitting with a column nut and a no hole ferrule Remove the old septum and replace it with a new one See To change the septum on the split splitless inlet Inspect the O ring and replace it if it is hard and brittle or cracked See To change the liner and O ring on the split splitless inlet Set the inlet to Split Mode Configure the column as Inlet Unspecified Set the inlet tempe
51. ck on This takes about two seconds The zero offset is used to correct future flow measurements To activate this select Calibration on the Options menu then choose either Front inlet or Back inlet press Enter and turn Auto flow zero on Zero conditions Flow sensors are zeroed with the carrier gas connected and flowing Pressure sensors are zeroed with the supply gas line disconnected from the gas control module Zero intervals Table 1 Flow and Pressure Sensor Zero Intervals Sensor type Module type Zero interval Flow All Use Auto flow zero and or Auto zero septum purge Pressure Inlets Packed columns Every 12 months Small capillary columns Every 12 months id 0 32 mm or less Large capillary columns At 3 months at 6 months id gt 0 32 mm then every 12 months Auxiliary channels Every 12 months Detector gases Every 12 months To zero a specific flow or pressure sensor 1 Press Options scroll to Calibration and press Enter 2 Scroll to the module to be zeroed and press Enter 3 Scroll to a zero line and press Info The GC will remind you of the conditions necessary for zeroing that specific sensor Flow sensors Verify that the gas is connected and flowing turned on Pressure sensors Disconnect the gas supply line at the back of the GC Turning it off is not adequate the valve may leak Advanced User Guide Options 4 4 Press On Yes to zero or Clear to cancel To zero all
52. cktable feature to begin Adjust offset at a specified time Aborting NPD adjust offset Press Delete with the cursor on the Adjust offset line This cancels the adjustment without turning off the detector gases and bead voltage Extending the NPD bead life These actions together with the automated heatup and adjust procedures can extend ceramic bead life considerably e Use the lowest practical Adjust offset value This will result in a lower Bead Voltage during operation e Run clean samples e Turn the bead off when not in use e Keep the detector temperature high 320 to 335 C e Turn the hydrogen flow off during solvent peaks and between runs Turning hydrogen off during a solvent peak When using the NPD the baseline shifts after a solvent peak and can take some time to stabilize especially with chlorinated solvents To minimize this effect turn off the hydrogen flow during the solvent peak and turn it back on after the solvent elutes With this technique the baseline recovers to its original value in less than 30 seconds This also extends the life of the bead The hydrogen can be turned on and off automatically as part of a Run Table See Run Time Programming on page 14 Advanced User Guide CAUTION Detectors 10 Turning hydrogen off between runs To extend bead life turn off the hydrogen flow between runs Leave all other flows and the detector temperature on Turn on the hydrogen flow for the ne
53. connected to the signal line will set a logic low state if proper base current is supplied e An open collector logic gate will perform this same function e A low side drive IC will also work but Darlington type drivers should be avoided as they will not meet the low side voltage requirement of less than 0 4V APG Remote connector Pin Function Logic 1 Digital ground 2 Prepare LOW true 1 3 Start LOW true input ge 4 Start relay 5 80 9 5 Start relay 6 not used 7 Ready HIGH true output 8 Stop LOW true 9 not used APG Remote signal descriptions Prepare Low True Request to prepare for analysis Receiver is any module performing pre analysis activities For example shorting pin 2 to ground will put the GC into Prep Run state This is useful for Splitless Mode to prepare the inlet for injection or when using the Gas Saver This function is not needed by Agilent autosampler systems Ready High True If The Ready Line is high gt 2 2 VDC then the system is ready for next analysis Receiver is any sequence controller 189 12 Cables Start Low True Request to start run timetable Receiver is any module performing runtime controlled activities The 7820A GC requires a pulse duration of at least 500 micro seconds to sense a start from an external device Start Relay Contact Closure A 120 millisecond contact closure used as an isolated output to start another device that is not compatib
54. ctor typically mounted over the back inlet Signal connector The two analog output signal 186 Advanced User Guide Cables 12 REMOTE connector Provides a port to remotely start and stop other instruments A maximum of 10 instruments can be synchronized using this connector See Using the Remote Start Stop cable on page 188 for more detail TEST PORT connector This connector is reserved for future development LAN connector Standard Local Area Network connector for communication with data systems and other devices Advanced User Guide 187 12 Cables Using the Remote Start Stop cable Remote start stop is used to synchronize two or more instruments For example you might connect an integrator and the GC so that the Start Stop buttons on either instrument control both of them You can synchronize a maximum of ten instruments using Remote cables Connecting Agilent products If connecting two Agilent products with Remote cables the sending and receiving circuits will be compatible just plug in both ends of the cable Connecting non Agilent products If connecting to a non Agilent product the following paragraphs contain information you will need to ensure compatibility APG Remote signal electrical specifications The APG signals are a modified open collector type The signal levels are generally TTL levels low voltage is logic zero high voltage is logic one but the open circuit voltage wil
55. delete the current timed event press Off No to cancel this operation To delete the entire table press Delete Clock Table Advanced User Guide Programming 2 Post Run Programming This function can be used with both isothermal and programmed methods Post run is a period that begins at the end of the normal run The parameters include e Time How long is the post run period e Oven Temperature What is the oven temperature during the post run period Column npres For a column controlled in a pressure mode enter the pressure for this column during the post run period Column nflow For a column controlled in a flow mode enter the flow rate for this column during the post run period Post run may be used to clean out a column in preparation for the next run backflush a column to eliminate high boilers and other functions When the Post run Time elapses the GC returns to the initial state defined in the current method To enable a post run program 1 Press Post Run 2 Type a non zero time for the post run duration and press Enter The post run parameters available for the current GC configuration appear 3 Scroll to each desired parameter type the value for the post run period and press Enter To disable a post run program 1 Press Post Run 2 Type a 0 as the post run time and press Enter Advanced User Guide 19 2 Programming 20 Advanced User Guide Agilent 7820A Gas C
56. detector contains a filament that is heated electrically so that it is hotter than the detector body The filament temperature is held constant while alternate streams of reference gas and column effluent pass over it When a sample component appears in the effluent the power required to keep the filament temperature constant changes The two gas streams are switched over the filament five times per second hence the ticking sound and the power differences are measured and recorded When helium or hydrogen is used as carrier gas the sample causes the thermal conductivity to fall If nitrogen is used the thermal conductivity usually goes up because most things are more conductive than nitrogen Because the TCD does not destroy the sample during the detection process this detector can be connected in series to a flame ionization detector or other detector Advanced User Guide Detectors 10 Column effluent Column effluent is forced away from is forced toward the filament TCD the filament TCD measures reference gas measures peaks if present Advanced User Guide 147 10 Detectors TCD pneumatics This is the pneumatics design of the TCD Makeup Reference gas Vent Reference switching valve PS Pressure Sensor Column TCD carrier reference and makeup gas Reference and makeup gas must be the same as the carrier gas and the gas type must be specified in both the inlet and detector parameter list
57. e e Calibrate both length and diameter using flow rate and elution time 47 4 48 Options CAUTION When you measure the column flow rate be sure to convert the measurement to normal temperature and pressure if your measurement device does not report data at NTP If you enter uncorrected data the calibration will be wrong To estimate the actual column length or diameter from an elution time 1 Set oven ramp 1 to 0 00 then verify that the column is defined Perform a run using an unretained compound and record the elution time Press Options scroll to Calibration and press Enter From the calibration list select the column and press Enter The GC displays the current calibration mode for the column To recalibrate or to change calibration mode press Mode Type to see the column calibration mode menu Scroll to Length or Diameter and press Enter The following choices appear Mode Measured flow Unretained peak Calculated length or Calculated diameter Not calibrated Scroll to Unretained peak and enter the actual elution time from the run performed above When you press Enter the GC will estimate the column length or diameter based on the elution time input and will now use that data for all calculations To estimate the actual column length or diameter from the measured flow rate 1 Set oven ramp 1 to 0 00 then verify that the column is defined Set the oven inlet and det
58. e TCD within 25 of the maximum response For further optimization adjust the reference flow 2m x 0 2 mm capillary column If column flow is 0 75 mL min the makeup must be at least 4 25 mL min Set it 5 Reference flow will then be 3 x 5 75 17 25 mL min Total detector flow 5 75 17 25 22 5 mL min 25 m x 0 32 mm capillary column If column flow 10 mL min set makeup low to minimize sample dilution Set it 2 mL min Reference flow will then be 12 x 2 24 mL min Total detector flow 12 24 36 mL min 153 10 Detectors About the uECD The micro cell detector uECD contains a cell plated with 63Ni a radioactive isotope The 63Ni releases B particles that collide with carrier gas molecules to produce low energy electrons each particle produces approximately 100 electrons The free electrons produce a small current called the reference or standing current that is collected and measured in a pulsed circuit When a sample component molecule comes into contact with the free electrons the electrons may be captured by the sample molecules to create negatively charged ions The voltage across the cell electrodes is pulsed to collect the remaining free electrons while the heavier ions are relatively unaffected and swept out the vent with the carrier gas flow Cell current is measured and compared to a reference current The pulse rate is adjusted to maintain a constant cell current The more uncaptured electrons
59. e column modes Advanced User Guide The flow modes available are determined by the GC inlet s control mode When the inlet s control mode is set to Pressure control all of the flow modes and pressure modes below are available for the column When the inlets control mode is set to Flowcontrol the column s mode is not selectable For an inlets mode of Flow control only column flow can be entered The flow modes Flow rates are corrected to NTP normal temperature and pressure 25 C and 1 atmosphere 133 134 Columns and Oven Select a column e Constant flow Maintains a constant mass flow rate of carrier gas in the column throughout the run If the column resistance changes due to a temperature program the column head pressure is adjusted to keep the flow rate constant This can shorten runs significantly e Ramped flow Increases the mass flow rate in the column during the run according to a program you enter A column flow profile can have up to three ramps each consisting of a programmed increase followed by a hold period The pressure modes The pressure modes are not available if the column is not defined or the inlet s mode is set to Flow control Pressures are gauge pressures the difference between the absolute pressure and the local atmospheric pressure Because most detectors present little resistance to the column flow the gauge pressure at the column head is usually the same as the pressure dif
60. ecomes ready inject 1 uL of the checkout sample and press Start on the GC Advanced User Guide ECD1 B C ECD D Hz4 12000 10000 8000 6000 4000 2000 Chromatographic Checkout 9 The following chromatogram shows typical results for a new detector with new consumable parts installed Lindane 18713 60040 5183 0379 Aldrin 18713 60040 Advanced User Guide 6B BT 2 min 5 71 5 Chromatographic Checkout To Check FPD Performance Sample 5188 5953 72 To check FPD performance first check the phosphorus performance then the sulfur performance Preparation 1 Gather the following Evaluation column HP 5 30 m x 0 32 mm x 0 25 um 19091J 413 FPD performance evaluation checkout sample 5188 5953 2 5 mg L 0 5 methylparathion in isooctane Phosphorus filter Sulfur filter and filter spacer 4 mL solvent and waste bottles or equivalent for autoinjector 2 mL sample vials or equivalent for sample Chromatographic grade isooctane for syringe wash solvent Inlet and injector hardware See To Prepare for Chromatographic Checkout 2 Verify the following Capillary column adapter installed If not install it Chromatographic grade gases plumbed and configured helium as carrier gas nitrogen hydrogen and air Empty waste vials loaded in sample turret 4 mL vial with diffusion cap filled with isooctane and inserted in Solvent A injector position
61. ectors temperatures to 35 C and allow them to cool to room temperature Remove the column from the detector Advanced User Guide Options 4 CAUTION When you measure the column flow rate be sure to convert the measurement to normal temperature and pressure if your measurement device does not report data at NTP If you enter uncorrected data the calibration will be wrong 4 Measure the actual flow rate through the column using a bubble meter Record the value Reinstall the column 5 Press Options scroll to Calibration and press Enter 6 From the calibration list select the column and press Enter The GC displays the current calibration mode for the column 7 To recalibrate or to change calibration mode press Mode Type to see the column calibration mode menu 8 Scroll to Length or Diameter and press Enter The following choices appear Mode Measured flow Unretained peak Calculated length or Calculated diameter Not calibrated 9 Scroll to Measured flow and enter the corrected column flow rate in mL min from the run performed above 10 When you press Enter the GC will estimate the column length or diameter based on the elution time input and will now use that data for all calculations To estimate the actual column length and diameter 1 Set oven ramp 1 to 0 00 then verify that the column is defined 2 Perform a run using an unretained compound and record the elution time 3 Set the oven
62. ed period press Enter a A Ww N Press Clear to reset the stopwatch 39 3 3 Configuration Valve 40 Up to 2 valves can be mounted in a temperature controlled valve box To configure a valve 1 Press Config Valve and enter the number of the valve you are configuring The current valve type is displayed To change the valve type press Mode Type select the new valve type and press Enter Valve types e Sampling Two position load and inject valve In load position an external sample stream flows through an attached gas sampling or internal liquid sampling loop and out to waste In inject position the filled sampling loop is inserted into the carrier gas stream When the valve switches from Load to Inject a run starts if one is not already in progress See the example in Gas sampling valve on page 183 Not installed Self explanatory Advanced User Guide Configuration 3 Front injector Back injector The injectors are normally plugged into the Front ALS Port on the GC when used for injections into the front inlet and the Back ALS Port on the GC when used for injections into the back inlet To configure the 7693A sampler system see the 7693A Installation Operation and Maintenance manual Advanced User Guide 41 3 Configuration Instrument 42 1 Press Config Scroll to Instrument and press Enter 2 Scroll to Serial Enter a serial number and press Enter
63. ent setpoints and modify as desired Repeat for each component as appropriate 3 Examine the current setpoints for the ALS if appropriate and modify as desired See To program the ALS on page 81 Advanced User Guide Methods and Sequences 6 4 Save the setpoints as a stored method See To save a method on page 81 To program the ALS 1 Press Front Injector or Back Injector Scroll to the desired setpoint Enter a setpoint value FP Ww N Save the setpoints as a stored method See To save a method on page 81 To save a method 1 Press Method and scroll to the desired method number 2 Press Store and On Yes to store the new method using the chosen number Alternatively press Off No to return to the stored methods list without saving the method A message is displayed if a method with the number you selected already exists Press On Yes to replace the existing method or Off No to return to the stored methods list without saving the method To load a stored method Press Load Method Supply the method number and press Enter The specified method will replace the current active method Method mismatch This section applies only to a standalone not connected to a data system GC When a data system such as a ChemStation or EZChrom Elite controls the GC methods are stored in the data system and can be edited there See your data system documentation for more inform
64. er Guide Chromatographic Checkout 5 Table 5 NPD Checkout Conditions Column and sample Type Sample Column mode Column flow Split splitless inlet Temperature Mode Purge flow Purge time Packed column inlet Temperature Detector Temperature H3 flow Air flow Makeup flow N3 Output Oven Initial temp Initial time Rate 1 Final temp Final time ALS settings if installed Sample washes Sample pumps Sample wash volume Injection volume HP 5 30 m x 0 32 mm x 0 25 pm 19091J 413 NPD checkout 18789 60060 Constant flow 6 5 mL min helium 200 C Splitless 60 mL min 0 75 min 200 C 300 C 3 mL min 60 mL min Makeup column 10 mL min 30 display units 30 pA 60 C 0 min 20 C min 200 C 3 min Tul 65 5 66 Chromatographic Checkout Table 5 NPD Checkout Conditions continued Syringe size 10 uL Solvent A pre washes 2 Solvent A post washes 2 Solvent A wash volume 8 Solvent B pre washes 0 Solvent B post washes 0 Solvent B wash volume 0 Injection mode Normal Airgap Volume 0 20 Viscosity delay 0 Inject Dispense Speed 7693A 6000 Prelnjection dwell 0 PostInjection dwell 0 Manual injection Injection volume Tul Data system Data rate 5 Hz 7 If using a data system prepare the data system to perform one run using the loaded checkout method Make sure that the data system will output a chromatogram 8 Start the run If performing an inject
65. er gas flow On until the oven has cooled This protects the column from oxygen damage Inlet preparation We are concerned with the possibility of burns and air intrusion into the column e After the oven and columns have cooled reduce all inlet flows to 0 0 and turn the temperatures Off e For inlet only maintenance leave all detectors at their normal setpoints except for the TCD filament which should be turned Off e If the column is to be removed cap both ends to keep air out Detector preparation This is another burn hazard area plus the possibility of damage to the very sensitive electronics Some detectors UECD FPD NPD require 12 hours or longer to stabilize from the detector off condition e To cool the detector reduce the temperature setpoint to 35 C e Some detectors FID NPD FPD use high voltages The high voltage supply is part of the electrometer Turn it Off to disable the high voltage e The filament in the TCD will be damaged if exposed to air while hot To protect the filament turn it Off Advanced User Guide Checking for Leaks 7 Leak Check Tips When checking for leaks consider the system in two parts external leak points and GC leak points e External leak points include the gas cylinder or gas purifier regulator and its fittings supply shutoff valves and connections to the GC supply fittings e GC leak points include inlets detectors column connections valve connecti
66. erate limit of a device To change the setting configuration properties for a Configured device 1 Press Config on the GC keypad and select a device from the list then press Enter In many cases you can move directly to the item of interest by pressing Config device 2 Scroll to the device setting and change the property This can involve making a selection from a list using Mode Type using On Yes or Off No or entering a numeric value Press Info for help on changing numeric settings or see the section of this document describing the specific configuration of the device Advanced User Guide 23 3 Configuration General Topics 24 Unlock the GC Configuration Ignore Ready Accessory devices including inlets detectors pressure controllers PCM and temperature control loops Thermal AUX have electrical connections to a power source and or the communication bus in the GC These devices must be assigned GC resources before they can be used Before assigning resources to a device you must first unlock the GC configuration If you try to configure an Unconfigured device without unlocking the GC configuration the GC displays the message CONFIGURATION IS LOCKED Go to Keyboard options to unlock It is also necessary to unlock the GC configuration if you are removing the GC resources from a Configured device This action returns the device state to Unconfigured To unlock the GC configuration press Op
67. ess Config device where device is one of the following Front Det Back Det 2 Scroll to Makeup gas type or Makeup reference gas type and press Mode Type 3 Scroll to the correct gas and press Enter Lit offset The GC monitors the difference between the detector output with the flame lit and the output when the flame is not lit If this difference falls below the setpoint the GC assumes that the flame has gone out and tries to reignite it See FID automatic reignition Lit offset on page 143 for details To configure the FPD heaters The flame photometric detector FPD uses two heaters one in the base and one near the combustion chamber When configuring the FPD heaters select Install Detector 2 htr rather than the default Install Detector FPD Advanced User Guide 31 3 32 Configuration To ignore the FID or FPD ignitor In general do not ignore the ignitor for normal operation Ignoring the ignitor also disables the Lit Offset and autoignition features which work together to shut down the detector if the detector flame goes out If the flame goes out under manual ignition GC will continue to flow hydrogen fuel gas into the detector and lab Use this feature only if the ignitor is defective and only until the ignitor is repaired If using an FID or FPD you can ignite the flame manually by setting the GC to ignore the ignitor 1 Press Config Front Det or Config Back Det 2 Scr
68. et temperature and column flow Make sure that a column is installed or the NPD column fitting is plugged before turning on the air or hydrogen An explosion may occur if air and hydrogen are allowed to leak into the oven Advanced User Guide 10 11 12 Select the bead white ceramic black ceramic Select the jet Install bead and jet as required See the Maintenance Manual for details Press Config Front Det or Config Back Det If you are using makeup gas verify that the configured makeup gas type is the same as that plumbed to your instrument Change the gas type if necessary Nitrogen is recommended If the displayed Bead Type is incorrect set the Bead Type using the Mode Type key Set Auto Adjust On recommended Set Dry Bead On recommended Press Front Det or Back Det Set the detector temperature The recommended range is 325 to 335 C Enter a hydrogen flow 3 0 mL min is recommended Turn the flow On Enter an air flow 60 is recommended for ceramic beads Turn the flow On a If you are using packed columns turn off makeup gas and proceed to step 13 b If your capillary column is defined choose a flow mode and set the makeup gas flow For a column in the constant flow mode choose Constant makeup For a 163 10 Detectors column in the constant pressure mode choose Column makeup constant c If your column is not defined enter a makeup gas flow Only constant fl
69. eters are turned on and off by pressing the On Yes or Off No keys Keyboard lock These keys and functions are operational when the keyboard lock is On Start Stop and Prep Run Load Method and Load Seq Seq to edit existing sequences Seq Control to start or stop sequences Hard configuration lock On prevents keyboard configuration changes Off removes lock Key click Click sound when keys are pressed Warning beep Allows you to hear warning beeps Warning beep mode There are 9 different warning sounds that may be selected This allows you to give multiple GCs individual voices We suggest you experiment Method modified beep Turn on for high pitched beep when method setpoint is modified Press Mode Type to change the pressure units and radix type Pressure units psi pounds per square inch lb in bar absolute cgs unit of pressure dyne cm kPa mks unit of pressure 10 N m Language Select English or Chinese or Japanese Radix type Determines the numeric separator type 1 00 or 1 00 Display saver If On dims the display after a period of inactivity If Off disabled Advanced User Guide Agilent 7820A Gas Chromatograph Advanced User Guide 5 Chromatographic Checkout About Chromatographic Checkout 54 To Prepare for Chromatographic Checkout 55 To Check FID Performance 56 To Check TCD Performance 60 To Check NPD Performance 64 To Check uECD Performance 68 To Chec
70. ference between column inlet and exit The mass selective detector and the atomic emission detector are the exceptions e Constant pressure Maintains a constant gauge pressure at the head of the column throughout the run If the column resistance and gas density changes during a run the gauge pressure does not change but the mass flow rate does e Ramped pressure Increases the column head gauge pressure during the run according to a program you enter A column pressure profile can have up to three ramps each consisting of a programmed increase followed by a hold period mode The column s mode parameter is not available if the inlet s mode parameter is set to Flow control 1 Press Col and enter the column number Scroll to the Mode line Press Mode Type to see the column mode list FP Ww N Scroll to the column mode you want Press Enter Advanced User Guide Columns and Oven 9 This completes column mode selection Next you must specify the inlet conditions either during the entire run if you selected either of the constant modes or at the beginning of the run if you selected either of the ramped modes Setting the column parameters for constant flow or constant pressure If the column is defined you can enter any one of these quantities the GC will calculate and display the other two For example you may have selected Constant pressure as the column mode You decide to specify as a starting cond
71. g Back Det 2 Scroll to Lit offset 3 Enter the new value and press Enter Recommended starting conditions for new FID methods See Table 22 for guidelines and rules to select initial detector settings for new methods Advanced User Guide 143 10 Detectors Table 22 Recommended starting conditions Combustible gas mix Make sure that the final hydrogen to air ratio is between 8 and 12 Detector temperature Set to 20 C above the highest oven temperature depending on the column type A temperature of 300 C provides a good starting point and easier ignition and minimizes water condensation The GC will not attempt to ignite the flame at a temperature lt 150 C Carrier gas flow hydrogen helium nitrogen Packed columns Suggest 10 to 60 mL min Capillary columns Suggest 1 to 5 mL min Detector gases Flow range mL min Suggested flow mL min Standard installation Column plus capillary makeup 10 to 60 30 Hydrogen 24 to 60 30 Air 200 to 600 400 With Nickel Catalyst Accessory Standard installation Column plus capillary makeup 10 to 60 30 Hydrogen 24 to 60 30 Air 200 to 600 400 Detector hydrogen is pressure controlled where the detector provides a known resistance If using a nickel catalyst tube the resistance changes and the flow rates displayed by the GC will not be accurate Measure the actual hydrogen flow using a flow meter at the detector vent with all other flows turned off Use nitroge
72. he PMT before removing the PMT housing or opening the emissions chamber Failing to do this can destroy the PMT Even with the PMT voltage off protect the PMT from room light Cap the housing when removed place it end down to exclude light reduce room light level before exposing the PMT and so on A brief exposure always with the PMT voltage turned off will not damage it but prolonged exposure will cause a gradual loss of sensitivity FPD optical filters The filters are marked on the edge with the transmission wavelength Each filter has a small arrow on its side which must point toward the PMT when installed The sulfur filter is silvery on both sides and transmits at 393 nanometers Advanced User Guide Detectors 10 The phosphorus filter is yellow green and transmits at 525 nanometers Inlet liners for use with the FPD Compounds containing sulfur may adsorb on an inlet liner and degrade the GC s performance Use deactivated clean liners or a cool on column inlet which injects directly onto the column For best results with splitless injection use liner 5181 3316 FPD temperature considerations FPD gas purity FPD gas flows Advanced User Guide The minimum detector temperature to prevent water condensation is 120 C We recommend a temperature that is 25 C higher than the highest column temperature but no higher than 250 C High purity gases have a lower sulfur content Standard purity gases ha
73. he cell must be returned for exchange Do not use solvents to clean the uECD You may not open the uECD cell unless authorized to do so by your local nuclear regulatory agency Do not disturb the four socket head bolts These hold the cell halves together United States customers removing or disturbing them is a violation of the terms of the exemption and could create a safety hazard Safety precautions when handling uECDs Never eat drink or smoke when handling uECDs Always wear safety glasses when working with or near open uECDs Wear protective clothing such as laboratory jackets safety glasses and gloves and follow good laboratory practices Wash hands thoroughly with a mild non abrasive cleaner after handling uECDs Cap the inlet and outlet fittings when the uECD is not in use Connect the uECD exhaust vent to a fume hood or vent it to the outside See the latest revision of title 10 Code of Federal Regulations part 20 including appendix B or the applicable State regulation For other countries consult with the appropriate agency for equivalent requirements Agilent Technologies recommends a vent line inside diameter of 6 mm 1 4 inch or greater With a line of this diameter the length is not critical Advanced User Guide Detectors 10 uECD gas flows Makeup Anode purge Vent 8Nj Capillary adapter t Column PS Pressure Sensor uECD linearity The uECD response factor ve
74. he remote start stop cable are listed in Table 35 Advanced User Guide 193 12 Cables 194 Table 35 Remote start stop cable connections Connector 1 9 pin male Connector 2 wire color Signal 1 Black Digital ground 2 White Prepare low tone 3 Red Start low tone 4 Green Start relay closed during start 5 Brown Start relay closed during start 6 Blue Open circuit 7 Orange Ready high true input 8 Yellow Stop low tone 9 Violet Open circuit Advanced User Guide Agilent 7820A Gas Chromatograph Advanced User Guide 13 GC Output Signals About Signals 196 Analog Signals 197 Analog zero 197 Analogrange 197 Analog datarates 198 Selecting fast peaks analog output 199 Digital Signals 200 Digital zero 200 Signal Freeze and Resume 200 Data rates with Agilent datasystems 201 Ee Agilent Technologies 195 13 GC Output Signals About Signals 196 Signal is the GC output to a data handling device analog or digital It can be a detector output or the output from flow temperature or pressure sensors One signal output channel is provided Signal output can be either analog or digital depending on your data handling device Analog output is available at either of two speeds suitable to peaks with minimum widths of 0 004 minutes fast data rate or 0 01 minutes normal rate Analog output ranges are 0 to 1 V 0 to 10 V and O to 1 mV Digital output rates are set by your Agilent da
75. her thermal conductivities than the carrier gas produce negative peaks For example helium or hydrogen form a negative peak with nitrogen or argon methane as the carrier gas Chemically active compounds reduce TCD filament life The tungsten rhenium TCD filament has been chemically passivated to protect against oxygen damage However chemically active compounds such as acids and halogenated 150 Advanced User Guide Detectors 10 compounds may attack the filament The immediate symptom is a permanent change in detector sensitivity due to a change in filament resistance If possible such compounds should be avoided If this is not possible the filament may have to be replaced frequently Changing the TCD polarity during a run Negative polarity On inverts the peak so the integrator or ChemStation can measure it Negative polarity can be a run table entry see Run Time Programming on page 14 Detecting hydrogen with the TCD using helium carrier gas Hydrogen is the only element with thermal conductivity greater than helium and mixtures of small amounts of hydrogen lt 20 in helium at moderate temperatures exhibit thermal conductivities less than either component alone If you are analyzing for hydrogen with helium carrier gas a hydrogen peak may appear as positive negative or as a split peak There are two solutions to this problem e Use nitrogen or argon methane as carrier gas This eliminates problems inheren
76. his line appears only if your columns in the flow path are defined Total flow This is the total flow into the inlet which is the sum of the split vent flow column flow and septum purge flow When you change the total flow the split ratio and split vent flow change while the column flow and pressure remain the same If all columns in the flow path are defined 1 Press Front Inlet or Back Inlet Scroll to Mode and press Mode Type Select Split Set the inlet temperature Aa WwW N If you want a specific split ratio scroll to Split ratio and enter that number Split flow will be calculated for you 5 If you want a specific split flow scroll to Split flow and enter that number Split ratio will be calculated for you 6 If desired turn on Gas saver Set Saver time after the injection time Press Prep Run see Pre Run and Prep Run on page 110 before manually injecting the sample If a column in the flow path is not defined 1 Press Front Inlet or Back Inlet 2 Set the inlet temperature Advanced User Guide Inlets 8 3 Set Total flow into the inlet Measure the split vent flow using a flow meter Subtract split vent flow and septum purge flow see Pre Run and Prep Run on page 110 from Total flow to get column flow Calculate the split ratio split vent flow column flow Adjust as needed Selecting parameters for the S SL splitless mode Advanced User Guide A successful splitless i
77. hromatograph Advanced User Guide 3 Configuration About Configuration 22 Assigning GC resources toa device 22 Setting configuration properties 23 General Topics 24 Unlock the GC Configuration 24 Ignore Ready 24 Information displays 25 Unconfigured 25 Oven 26 Front Inlet Back Inlet 27 Column 28 To configure a single column 28 Front Detector Back Detector 31 Lit offset 31 To configure the FPD heaters 31 Analog Out 33 Fast peaks 33 Valve Box 34 Thermal Aux 35 To configure a MSD transfer line heater 35 To configure a nickel catalyst heater 35 PCM A PCMB 37 Status 38 The Ready Not Ready status table 38 The setpoint status table 38 Time 39 Valve 40 Front injector Back injector 41 Instrument 42 pe Agilent Technologies 21 3 Configuration About Configuration Configuration is a two part process for most GC accessory devices that require power and or communication resources from the GC In the first part of the configuration process a power and or communication resource is assigned to the device The second part of the configuration process allows setting of any configuration properties associated with the device Assigning GC resources to a device 22 A hardware device requiring but not assigned GC resources is given a mode of Unconfigured by the GC Once you assign GC resources to a device the GC gives the device a mode of Configured allowing you to access other property settings if any for the device T
78. ide 115 8 inlets If you are using gas saver the gas saver time should be after the purge time Split Carrier Supply Septum Purge 80 PSI EPC Module Split Vent Trap Inlet Weldment FS Flow Sensor PS Pressure Sensor Column The S SL inlet pulsed split and splitless modes The pressure pulse modes increase inlet pressure just before the beginning of a run and return it to the normal value after a specified amount of time The pressure pulse e reduces the solvent vapor volume e reduces the risk of inlet overload e tightens the sample band e may allow use of a 2 mm liner reducing the active glass area If your chromatography is degraded by the pressure pulse a retention gap may help restore peak shape 116 Advanced User Guide Inlets 8 You must press Prep Run before doing manual injections in the pressure pulse modes See Pre Run and Prep Run on page 110 for details You can do column pressure and flow programming when in the pressure pulse mode However the pressure pulse will take precedence over the column pressure or flow ramp Pressure pulse Pressure or Flow Pressure or flow program Split Splitless inlet split mode minimum operating pressures The minimum recommended inlet total flow is 20 mL minute When the split splitless inlet is operated in Split mode there will be a minimum pressure at which the inlet can operate Typically low inlet pressures may be re
79. ide 63 5 Chromatographic Checkout To Check NPD Performance 1 Gather the following Evaluation column HP 5 30 m x 0 32 mm x 0 25 um 19091J 413 NPD performance evaluation checkout sample 18789 60060 4 mL solvent and waste bottles or equivalent for autoinjector Chromatographic grade isooctane 2 mL sample vials or equivalent for sample Inlet and injector hardware See To Prepare for Chromatographic Checkout 2 Verify the following Capillary column jet installed If not select and install a capillary column jet Capillary column adapter installed If not install it Chromatographic grade gases plumbed and configured helium as carrier gas nitrogen hydrogen and air Empty waste vials loaded in sample turret 4 mL vial with diffusion cap filled with isooctane and inserted in Solvent A injector position 3 Replace consumable parts liner septum traps syringe and so forth as needed for the checkout See To Prepare for Chromatographic Checkout 4 If present remove any protective caps from the inlet manifold vents 5 Install the evaluation column See the procedure for the SS or PP in the Maintenance manual Bake out the evaluation column for at least 30 min at 180 C See the procedure for the SS or PP in the Maintenance manual Be sure to configure the column 6 Create or load a method with the parameter values listed in Table 5 64 Advanced User Guide Advanced Us
80. iew 107 Carrier Gas Flow Rates 108 About Gas Saver 109 To use gas saver 109 Pre Run and Prep Run 110 The Prep Run key 110 Auto Prep Run 111 About Heaters 112 About the Split Splitless Inlet 114 Septum tightening S SL 114 Split Splitless inlet split mode overview 114 Split Splitless inlet splitless mode overview 115 The S SL inlet pulsed split and splitless modes 116 Split Splitless inlet split mode minimum operating pressures 117 Selecting the correct S SL inlet liner 118 Vapor Volume Calculator 120 Setting parameters for the S SL split mode 120 Selecting parameters for the S SL splitless mode 121 Setting parameters for the S SL splitless mode 122 Setting parameters for the S SL pulsed modes 123 About the Packed Column Inlet 124 Setting parameters 124 9 Columns and Oven About the Oven 128 Oven safety 128 Configuring the Oven 129 About Oven Temperature Programming 130 Programming setpoints 130 Ovenramprates 131 Setting the oven parameters for constant temperature 131 Setting the oven parameters for ramped temperature 132 Advanced User Guide 10 Detectors Advanced User Guide About Columns 133 Selecting the correct packed glass columntype 133 About the column modes 133 Selecta column mode 134 Setting the column parameters for constant flow or constant pressure 135 Enter a flow or pressure program optional 135 Programming column pressure or flow 136 Nickel Catalyst Tube 137 About the nickel catalysttu
81. inlet and detectors temperatures to 35 C and allow them to cool to room temperature 4 Remove the column from the detector Advanced User Guide 49 4 Options CAUTION When you measure the column flow rate be sure to convert the measurement to normal temperature and pressure if your measurement device does not report data at NTP If you enter uncorrected data the calibration will be wrong 50 10 11 12 Measure the actual flow rate through the column using a bubble meter Record the value Reinstall the column Press Options scroll to Calibration and press Enter From the calibration list select the column and press Enter The GC displays the current calibration mode for the column To recalibrate or to change calibration mode press Mode Type to see the column calibration mode menu Scroll to Length amp diameter and press Enter The following choices appear Mode Measured flow Unretained peak Calculated length Calculated diameter Not calibrated Scroll to Measured flow and enter the corrected column flow rate in mL min from the run performed above Scroll to Unretained peak and enter the actual elution time from the run performed above When you press Enter the GC will estimate the column length or diameter based on the elution time input and will now use that data for all calculations Advanced User Guide Options 4 Communication Configuring the IP address for the GC
82. installing a new liner and septum ensures that they will not contribute any contamination to the results 1 Check the indicators dates on any gas supply traps Replace recondition expended traps 2 Install new consumable parts for the inlet and prepare the correct injector syringe and needle as needed Table 2 Recommended parts for checkout by inlet type Recommended part for checkout Part number Split splitless inlet Syringe 10 uL 5181 1267 O ring 5188 5365 Septum 5183 4757 Liner 5062 3587 or 5181 3316 Packed column inlet Syringe 10 uL 5181 1267 O ring 5080 8898 Septum 5183 4757 55 5 To Check FID Performance 56 Chromatographic Checkout Gather the following Evaluation column HP 5 30 m x 0 32 mm x 0 25 um 19091J 413 FID performance evaluation checkout sample 5188 5372 Chromatographic grade isooctane 4 mL solvent and waste bottles or equivalent for autoinjector 2 mL sample vials or equivalent for sample Inlet and injector hardware See To Prepare for Chromatographic Checkout 2 Verify the following Capillary column jet installed If not select and install a capillary column jet Capillary column adapter installed adaptable FID only If not install it Chromatographic grade gases plumbed and configured helium as carrier gas nitrogen hydrogen and air Nitrogen is an acceptable alternate carrier gas Empty waste vials loaded in sample turret 4 mL s
83. ion using an autosampler start the run using the data system or creating a one sample sequence and pressing Start on the GC If performing a manual injection with or without a data system a Press Prep Run to prepare the inlet for splitless injection b When the GC becomes ready inject 1 uL of the checkout sample and press Start on the GC 9 The following chromatogram shows typical results for a new detector with new consumable parts installed Advanced User Guide Chromatographic Checkout 5 NPD1 B C NPD D Malathion pA 70 60 Azobenzene 50 40 30 204 Octadecane Advanced User Guide 67 5 Chromatographic Checkout To Check uECD Performance 1 Gather the following Evaluation column HP 5 30 m x 0 32 mm x 0 25 um 19091J 413 uECD performance evaluation checkout sample 18713 60040 Japan 5183 0379 4 mL solvent and waste bottles or equivalent for autoinjector Chromatographic grade isooctane 2 mL sample vials or equivalent for sample Inlet and injector hardware See To Prepare for Chromatographic Checkout 2 Verify the following Clean fused silica indented mixing liner installed If not install it Chromatographic grade gases plumbed and configured helium for carrier gas nitrogen for makeup Nitrogen is an acceptable alternate carrier gas Empty waste vials loaded in sample turret 4 mL vial with diffusion cap filled with hexane a
84. ions 4 Calibration Press Calibration to list the parameters that can be calibrated These include e Inlets e Detectors e ALS e Columns e Oven e Atmospheric pressure In general you will only need to calibrate the EPC modules and capillary columns ALS oven and atmospheric pressure calibration should only be performed be trained service personnel The calibration displays are discussed in the Agilent 7820A Service Manual Maintaining EPC calibration inlets detectors and PCM The EPC gas control modules contain flow and or pressure sensors that are calibrated at the factory Sensitivity slope of the curve is quite stable but zero offset requires periodic updating Flow sensors The split splitless and purged packed inlet modules use flow sensors If the Auto flow zero feature see page 45 is on they are zeroed automatically after each run This is the recommended way They can also be zeroed manually see To zero a specific flow or pressure sensor Pressure sensors All EPC control modules use pressure sensors They can be zeroed as a group or individually There is no automatic zero for pressure sensors Auto flow zero A useful calibration option is Auto flow zero When it is On after the end of a run the GC shuts down the flow of gases to an inlet waits for the flow to drop to zero measures and Advanced User Guide 45 4 46 Options stores the flow sensor output and turns the gas ba
85. iting clock time events 18 Deleting clock time events 18 Post Run Programming 19 To enable a post run program 19 To disable a post run program 19 3 Configuration About Configuration 22 Assigning GC resources to a device 22 Setting configuration properties 23 General Topics 24 Unlock the GC Configuration 24 Ignore Ready 24 Information displays 25 Unconfigured 25 Oven 26 To configure the oven 26 Front Inlet Back Inlet 27 To configure the Gas type 27 Column 28 To configure a single column 28 To view a summary of column connections 30 Advanced User Guide 4 Options Front Detector Back Detector 31 To configure the makeup reference gas 31 Lit offset 31 To configure the FPD heaters 31 To ignore the FID or FPD ignitor 32 Analog Out 33 Fast peaks 33 Valve Box 34 To assign a GC power source to a valve box heater 34 Thermal Aux 35 To assign a GC power source to an Aux thermal zone 35 To configure a MSD transfer line heater 35 To configure a nickel catalyst heater 35 PCM A PCMB 37 To assign a GC communication source toa PCM 37 To configureaPCM 37 Status 38 The Ready Not Ready status table 38 The setpoint status table 38 To configure the setpoint status table 38 Time 39 To set time and date 39 To use the stopwatch 39 Valve 40 To configure a valve 40 Front injector Back injector 41 Instrument 42 About Options 44 Calibration 45 Maintaining EPC calibration inlets detectors and PCM 45 To zero all pressure
86. ition the column flow The GC will compute the pressure necessary to achieve this flow as well as the average linear velocity and hold this pressure constant during the run If you select Constant flow as the mode and specify column flow as the initial condition the GC will still calculate the pressure necessary to achieve this flow but it will adjust the pressure as necessary to maintain constant flow If the column is not defined you can enter only pressure Constant flow can still be specified but the GC cannot know what the flow is 1 Press Col and enter the column number 2 Scroll to the Pressure or Flow or Velocity line 3 Type the desired initial value followed by Enter The GC will compute and display the other two values Adjust them if you choose to by repeating steps 2 and 3 but note that changing any one changes all three This completes setting the initial carrier gas condition Enter a flow or pressure program optional Advanced User Guide If you selected either the ramped pressure or ramped flow column mode the column parameter list contains entries for setting up a ramp program You begin with an initial value either Initial Pressure or Initial Flow and an Initialtime At the end of that time Rate1 begins and runs until it reaches Final pressure or Final flow It remains at that value for Final time 1 You can then add a second and third ramp each consisting of a Rate a Final value pressure
87. ition the filled sampling loop is inserted into the carrier gas stream When the valve switches from Load to Inject it starts a run if one is not already in progress See the example on page 183 Not installed Self explanatory 181 182 11 Valves Configuring a Valve Press Config Scroll to Valve Enter the valve number and press Enter The current valve type is displayed To change the valve type press Mode Type select the new valve type and press Enter Advanced User Guide Valves 11 Controlling a Valve From the keyboard Valves have two positions controlled by the On and Off keys The keyboard commands for two position valves are Valve lt scroll to the valve gt On Rotates valve to one stop and Valve lt scroll to the valve gt Off Rotates valve to the other stop From the run or clock time tables The Valve On and Valve Off commands can be run time or clock time programmed See Run Time Programming on page 14 and Clock Time Programming on page 17 If a valve is rotated by a run time program it is not automatically returned to its initial position at the end of the run You must program this reset operation yourself Gas sampling valve If a valve is configured as a gas sampling valve it starts a run automatically when it is switched to the Inject position This can be done with a keyboard command or by a subsequence or clock table entry You may have two
88. ive chemicals must not be introduced into the detector and the effluent from the detector must be vented outside the laboratory environment Materials that may react with the 63N i source either to form volatile products or to cause physical degradation of the plated film must be avoided These materials include oxidizing compounds acids wet halogens wet nitric acid ammonium hydroxide hydrogen sulfide PCBs and carbon monoxide This list is not exhaustive but indicates the kinds of compounds that may cause damage to 63 i detectors In the extremely unlikely event that both the oven and the detector heated zone should go into thermal runaway maximum uncontrolled heating in excess of 400 C at the same time and that the detector remains exposed to this condition for more than 12 hours take the following steps Advanced User Guide e After turning off the main power and allowing the instrument to cool cap the detector inlet and exhaust vent openings Wear disposable plastic gloves and observe normal laboratory safety precautions e Return the cell for exchange following directions included with the License Verification Form part no 19233 90750 155 10 Detectors 156 e Include a letter stating the condition of abuse It is unlikely even in this very unusual situation that radioactive material will escape the cell However permanent damage to the Ni plating within the cell is possible and therefore t
89. k FPD Performance Sample 5188 5953 72 Ee Agilent Technologies 53 5 Chromatographic Checkout About Chromatographic Checkout 54 The tests described in this section provide basic confirmation that the GC and detector can perform comparably to factory condition However as detectors and the other parts of the GC age detector performance can change The results presented here represent typical outputs for typical operating conditions and are not specifications The tests assume the following e Use of an automatic liquid sampler If not available use a suitable manual syringe instead of the syringe listed e Use of a 10 uL syringe in most cases However a 5 uL syringe is an acceptable substitute for the 1 uL injections described here e Use of the septa and other hardware liners jets adapters and so forth described If you substitute other hardware performance can vary Selected tests described in this section can be run automatically using the documentation and utility DVD provided with your GC Advanced User Guide Chromatographic Checkout 5 To Prepare for Chromatographic Checkout Advanced User Guide Because of the differences in chromatographic performance associated with different consumables Agilent strongly recommends using the parts listed here for all checkout tests Agilent also recommends installing new consumable parts whenever the quality of the installed ones is not known For example
90. l be between 2 5 and 3 7 Volts The typical voltage is 3 Volts A voltage over 2 2 volts will be interpreted as a high logic state while a voltage below 0 4 volts will be interpreted as a low logic state These levels provide some margin over the specifications of the devices used The pull up resistance connected to the open circuit voltage is in the range of about 1K ohms to 1 5K ohms For a logic low state for a single device on the bus the minimum current you must be able to sink is 3 3 milliamps Since devices are connected in parallel when you have multiple devices this minimum current must be multiplied by the number of devices attached on the bus The maximum voltage for a low input state 0 4V The bus is passively pulled high Leakage current out of a port must be less than 0 2 milliamps to keep the voltage from being pulled lower than 2 2 volts Higher leakage current may cause the state to be interpreted as a low Over voltage protection APG Remote connections are clamped by a zener diode to 5 6 Volts Exceeding this voltage will damage the circuit main board 188 Advanced User Guide Advanced User Guide Cables 12 APG Remote Suggested drive circuits A signal on the APG bus may be driven by another APG device or by one of the following circuits e A relay with one side connected to ground when closed will set a logic low state e An NPN transistor with the emitter connected to ground and the collector
91. le 31 Valve drivers A valve driver is the software and circuitry in the GC that controls a valve or related function There are two drivers known as Valve 1 and Valve 2 If a third valve is installed one of these two drivers controls two valves at the same time Valve number Type Volts Power or current Use 1 and 2 Current source 24 VDC 13 watts Pneumatic valve control The internal valve drivers Advanced User Guide Valve drivers 1 through 2 are usually used to control pneumatically operated valves mounted in the valve box The wiring for these appears at a set of connectors inside the right cover of the GC Pneumatically driven valves are controlled by solenoids mounted near the connectors that control the flow of air to the valve actuators Keyboard or Connector V1 Internal valve drivers or Connector v2 Clock table 179 11 Valves 180 There is no direct relationship between the location of a valve in the valve box and the driver that controls it This depends on how the solenoids are wired and the actuators are plumbed Manual valves must be switch by hand and are heated or unheated Advanced User Guide Valve Types Advanced User Guide Valves 11 There possible valve types are Sampling A two position load and inject valve In load position an external sample stream flows through an attached gas sampling or internal liquid sampling loop and out to waste In inject pos
92. le or connected with APG Remote pin 3 Stop Low True Request to reach system ready state as soon as possible for example stop run abort or finish and stop injection Receiver is any module performing runtime controlled activities Normally this line is not connected if the GC oven program is used to control the method Stop time APG Remote timing diagram Waiting for Ready System Ready Request for Prepare Not Ready during Prep System Ready Start Requested Injection cycle started Injection Start Runtime elapsed Start Waiting for Ready System Ready Prepare H il Start H a e L Stop H L U o_O E Ready L 190 Advanced User Guide Connecting Cables Cables 12 Connect a GC to an Agilent data system computer using LAN communications using a LAN cable See Figure 5 below LAN cable 8121 0940 LAN hub switch or Crossover LAN cable 5183 4648 LAN cable LAN cable 8121 0940 8121 0940 GC Computer Gc Computer Figure 5 Connecting the GC and computer with a hub switch shown at left or a crossover cable shown at right Advanced User Guide Table 32 Typical IP addresses for an isolated LAN GC Computer IP address 192 168 0 26 192 168 0 1 Subnet mask 255 255 255 0 255 255 255 0 A single communications LAN cable is supplied with the GC The switch or hub and other cables must be ordered separately if needed See Table 32 and T
93. litless injection b When the GC becomes ready inject 1 uL of the checkout sample and press Start on the GC 10 The following chromatogram shows typical results for a new detector with new consumable parts installed and nitrogen makeup gas C15 C16 C13 C14 Advanced User Guide jt min 59 5 To Check TCD Performance 60 Chromatographic Checkout Gather the following Evaluation column HP 5 30 m x 0 32 mm x 0 25 um 19091J 413 FID TCD performance evaluation checkout sample 18710 60170 4 mL solvent and waste bottles or equivalent for autoinjector Chromatographic grade hexane 2 mL sample vials or equivalent for sample Chromatographic grade helium as carrier makeup and reference gas Inlet and injector hardware See To Prepare for Chromatographic Checkout Verify the following Chromatographic grade gases plumbed and configured helium as carrier gas and reference gas Empty waste vials loaded in sample turret 4 mL solvent vial with diffusion cap filled with hexane and inserted in Solvent A injector position Replace consumable parts liner septum traps syringe and so forth as needed for the checkout See To Prepare for Chromatographic Checkout Install the evaluation column See the procedure for the SS or PP in the Maintenance manual Bake out the evaluation column for at least 30 min at 180 C See the procedure for the SS or PP i
94. lly 2 pA On 70 C 0 min 25 C min 73 5 74 Chromatographic Checkout Table 7 Final temp 1 Final time 1 Rate 2 Final temp 2 Final time 2 ALS settings if installed Sample washes Sample pumps Sample wash volume Injection volume Syringe size Solvent A pre washes Solvent A post washes Solvent A wash volume Solvent B pre washes Solvent B post washes Solvent B wash volume Injection mode Airgap Volume Viscosity delay Inject Dispense Speed 7693A Prelnjection dwell Postlnjection dwell Manual injection Injection volume Data system Data rate FPD Checkout Conditions continued P 150 C 0 min 5 C min 190 C 4 min 1 uL 10 uL oOo oO O N N Normal 0 20 0 6000 1 pL 5 Hz 8 Ignite the FPD flame if not lit 9 Display the signal output and monitor This output typically runs between 40 and 55 but can be as high as 70 Wait for the output to level off This takes approximately 1 hour Advanced User Guide Advanced User Guide 10 11 12 Chromatographic Checkout 5 If the baseline output is too high Check column installation If installed high the stationery phase burns out and increases measured output Check for leaks Bake out the detector and column at 250 C Wrong flows set for installed filter If the baseline output is zero verify the electrometer is on and the flame is lit If using a data system prepare the data system to
95. n makeup gas instead of helium for greater sensitivity Setting parameters for FID WARNING Verify that a column is installed or the FID column fitting is plugged before turning on the air or hydrogen An explosion may occur if air and hydrogen are allowed to leak into the oven 144 Advanced User Guide Advanced User Guide Detectors 10 To set the FID parameters 1 Verify Makeup gas is configured Installed jet type is correct for column type Press Front Det or Back Det Set the detector temperature The temperature must be greater than 150 C for the flame to light Set the hydrogen flow rate if desired and press Off No Change the air flow rate if desired and press Off No If using a packed column set the FID makeup gas to 0 0 Off If using a defined capillary column set the makeup gas flow or combined column plus makeup gas flow Scroll to Flame and press On Yes This turns on the air and hydrogen and initiates the ignition sequence The signal typically increases to 5 to 20 pA after ignition Verify that the flame is lit by holding a cold shiny surface such as a mirror or chrome plated wrench over the collector exit Steady condensation indicates that the flame is lit 145 10 Detectors About the TCD 146 The TCD compares the thermal conductivities of two gas flows pure carrier gas the reference gas and carrier gas plus sample components the column effluent This
96. n the Maintenance manual Configure the column Create or load a method with the parameter values listed in Table 4 Table 4 TCD Checkout Conditions Column and sample Type HP 5 30 m x 0 32 mm x 0 25 pm 19091J 413 Sample FID TCD checkout 18710 60170 Advanced User Guide Advanced User Guide Chromatographic Checkout 5 Table 4 TCD Checkout Conditions continued Column flow Column mode Split splitless inlet Temperature Mode Purge flow Purge time Packed column inlet Temperature Detector Temperature Reference flow He Makeup flow He Baseline output Oven Initial temp Initial time Rate 1 Final temp Final time Rate 2 Final temp Final time ALS settings if installed Sample washes Sample pumps Sample wash volume Injection volume Syringe size Solvent A pre washes Solvent A post washes 6 5 mL min Constant flow 250 C Splitless 60 mL min 0 75 min 250 C 300 C 20 mL min 2 mL min lt 30 display counts on Agilent ChemStation lt 750 pV 40 C 0 min 20 C min 90 C 0 min 15 C min 170 C 0 min Tul 10 pL 61 5 62 Chromatographic Checkout Table 4 TCD Checkout Conditions continued Solvent A wash volume Solvent B pre washes Solvent B post washes Solvent B wash volume Injection mode Airgap Volume Viscosity delay Inject Dispense Speed 7693A Prelnjection dwell Postlnjection dwell Manual injection Injection volume Data sy
97. nd inserted in Solvent A injector position 3 Replace consumable parts liner septum traps syringe and so forth as needed for the checkout See To Prepare for Chromatographic Checkout 4 Install the evaluation column See the procedure for the SS or PP in the Maintenance manual Bake out the evaluation column for at least 30 minutes at 180 C See the procedure for the SS or PP in the Maintenance manual Be sure to configure the column 5 Display the signal output to determine baseline output A stable baseline output at any value between 0 5 and 1000 Hz ChemStation display units inclusive is acceptable If the baseline output is lt 0 5 Hz verify that the electrometer is on If the offset is still lt 0 5 Hz your detector requires service 68 Advanced User Guide Advanced User Guide Chromatographic Checkout 5 If the baseline output is gt 1000 Hz there may be chemical contamination contributing to the signal Bakeout the uECD If repeated cleanings do not give an acceptable signal check gas purity Use higher purity gases and or install traps 6 Create or load a method with the parameter values listed in Table 6 Table 6 uECD Checkout Conditions Column and sample Type Sample Column mode Column flow Split splitless inlet Temperature Mode Purge flow Purge time Packed column inlet Temperature Detector Temperature Makeup flow N3 Baseline output Oven Initial
98. nd Agencies of the U S Gov ernment will receive no greater than Restricted Rights as defined in FAR 52 227 19 c 1 2 June 1987 U S Govern ment users will receive no greater than Limited Rights as defined in FAR 52 227 14 June 1987 or DFAR 252 227 7015 b 2 November 1995 as applicable in any technical data Safety Notices CAUTION A CAUTION notice denotes a hazard It calls attention to an operating procedure practice or the like that if not correctly performed or adhered to could result in damage to the product or loss of important data Do not proceed beyond a CAUTION notice until the indicated conditions are fully understood and met A WARNING notice denotes a hazard It calls attention to an operating procedure practice or the like that if not correctly performed or adhered to could result in personal injury or death Do not proceed beyond a WARNING notice until the indicated conditions are fully understood and met Firmware Version This manual is written for 7820A GCs using firmware version A 01 12 Contents 1 Software Keypad Using the Software Keypad 12 2 Programming Run Time Programming 14 Using runtime events 14 Programming runtime events 15 Theruntable 15 Adding events to the run table 15 Editing events in the run table 15 Deleting run time events 16 Clock Time Programming 17 Using clock time events 17 Programming clock time events 17 Adding events to the clock table 18 Ed
99. njection consists of these steps 1 2 Vaporize the sample and solvent in a heated inlet Use a low flow and low oven temperature to create a solvent saturated zone at the head of the column Use this zone to trap and reconcentrate the sample at the head of the column Wait until all or at least most of the sample has transferred to the column Then discard the remaining vapor in the inlet which is mostly solvent by opening a purge valve This eliminates the long solvent tail that this vapor would otherwise cause Raise the oven temperature to release the solvent and then the sample from the head of the column Some experimentation is needed to refine the operating conditions Table 16 provides starting values for the critical parameters Table 16 Splitless mode inlet parameters Parameter Allowed setpoint range Suggested starting value Oven temperature 24 C to 425 C 10 C below solvent boiling point Oven initial time 0 to 999 9 minutes gt Inlet purge time Inlet purge time 0 to 999 9 minutes 2 x Liner volume Column flow Gas saver time 0 to 999 9 minutes After purge time Gas saver flow 15 to 1000 mL min 15 mL min greater than maximum column flow 121 122 Setting parameters for the S SL splitless mode Mode The current operating mode splitless Oven temperature Below solvent boiling point Temperature Actual and setpoint inlet temperatures Pressure Actual and setpoint inlet pressure in psi
100. nnection and so forth The pressure decay leak test described below requires removing the column and capping the inlet column fitting This test can cannot find the following types of leaks The test can find leaks at the The test cannot find leaks at the septum column fitting septum nut gas supply bulkhead fittings to the flow module glass insert O ring seal adapter and ferrule inlet body top insert weldment seals within the tubing between the inlet flow module and the inlet body This leak test is not appropriate for flammable carrier gases such as hydrogen Advanced User Guide 1 Gather the following see Consumables and parts for the purged packed inlet No hole ferrule 1 4 inch wrench 7 16 inch wrench Heat resistant gloves if the inlet is hot 9 16 inch wrench 99 7 100 Checking for Leaks 10 1 8 and 1 4 inch Swagelok caps ECD TCD Detector plug part no 5060 9055 Load the inlet maintenance method and wait for the GC to become ready Remove the column if installed Plug the column fitting If the capillary column adapter is installed use a column nut and a no hole ferrule If a 1 8 inch packed column adapter is installed use a 1 8 inch Swagelok cap 5180 4121 If a 1 4 inch packed column adapter is installed use a 1 4 inch Swagelok cap 5180 4120 Remove the old septum and replace it with a new one See To change the septum on the purged packed inlet Inspect the
101. numeric order All heated valves in a valve box are controlled by the same temperature setpoint To assign a GC power source to a valve box heater 1 Unlock the GC configuration press the Options key select Keyboard amp Display and press the Enter key Scroll down to Hard Configuration Lock and press the off button 2 Press Config scroll to Valve Box and press Enter 3 With Unconfigured selected press Mode type select one of the following and press Enter Install heater A1 for a valve box containing a single heater plugged into the connector labeled Al on the valve box bracket Install Heater A2 for a valve box containing a single heater plugged into the connector labeled A2 on the valve box bracket The valve box bracket is located inside the GC right side electrical compartment in the upper right location 4 When prompted by the GC turn the power off then on again This completes the configuration of the valve box To set the valve box temperature for your method press the valve key and scroll to Valve Box 34 Advanced User Guide Configuration 3 Thermal Aux See Unconfigured on page 25 and Ignore Ready on page 24 The GC provides one additional channel of temperature control Thermal Aux 1 To assign a GC power source to an Aux thermal zone This procedure assigns the heater power source from heater plug Al to the Thermal Aux 1 temperature control zone 1 Unlock the
102. o assign GC resources to a device with an Unconfigured mode 1 Unlock the GC configuration Press Options select Keyboard amp Display and press Enter Scroll down to Hard Configuration Lock and press Off No 2 Press Config on the GC keypad and select a device from the list then press Enter The Config key opens a menu similar to this Oven Front inlet Back Inlet Column Front detector Back detector Analog out Valve Box Thermal Aux 1 PCM A PCM B Status Time Valve Injector Instrument In many cases you can move directly to the item of interest by pressing Config device Advanced User Guide Configuration 3 3 When the Configure Device Display opens the cursor should be on the Unconfigured field Press Mode Type and follow the GC prompts to assign resources to the device 4 After assigning resources the GC prompts for you to power cycle the GC Turn the GC power switch off and then on When the GC starts select the device just assigned the GC resources for further configuration if needed When accessed its mode should indicate Configured and the other configuration properties are displayed Setting configuration properties A device s configuration properties are constant for an instrument hardware setup unlike method settings which can change from sample run to sample run An example of a configuration setting is the gas type flowing through a pneumatic device or the operation temp
103. o program a valve subsequence 85 To program post sequence events 85 To save a sequence 86 To load a stored sequence 86 To determine sequence status 86 To start a sequence 86 To pause and resume a sequence 87 To stop a sequence 87 To abort a sequence 87 pe Agilent Technologies 79 6 Methods and Sequences Creating Methods A method is the group of setpoints needed to run a single sample on the GC such as oven temperature programs pressure programs inlet temperatures sampler parameters etc A method is created by saving a group of setpoints as a numbered method using the Store key Components for which setpoint parameters can be stored are shown in Table 9 Table 9 Setpoint parameter components Component Component Oven Analog Out Valve 1 2 Front and back injector see the ALS operating manual Front and back inlet Aux temp Columns 1 to 4 Post run Front and back detector Run table The GC also saves ALS setpoints See the 7693A Installation Operation and Maintenance manual for details on its setpoints Setpoint parameters are saved when the GC is turned off and loaded when you turn the instrument back on However if the hardware was changed while the instrument was turned off it may not be possible to restore all setpoints in the method To program a method 80 1 Individually select each component for which setpoint parameters are appropriate for your method See Table 9 2 Examine the curr
104. o program events to occur during a day based on the 24 hour clock Clock table events that would occur during a run or sequence are ignored For example the clock table could be used to make a blank run before you even get to work in the morning Programming clock time events 1 Press Clock Table Press Mode Type to see the available clock time events Scroll to the parameter to be programmed Edit Time and the setpoints for this event oa A w N Press Mode Type to add another event Press Status to terminate entries When the clock event is executed a confirming message appears Advanced User Guide 17 18 2 Programming Adding events to the clock table 1 Press Clock Table Press Mode Type When entries are added they are automatically ordered chronologically 3 Select the event type 4 Set appropriate parameters 5 Repeat this process until all entries are added Editing clock time events Press Clock Table to view all events programmed 2 Scroll to the event you want to change To edit the time for an event move the cursor to the line labelled Time and type the desired time To edit a setpoint value scroll to the setpoint item Press On Yes or Off No or enter a numerical value for the setpoint Deleting clock time events 1 Press Clock Table 2 Use Delete to remove events from the clock time table You will be asked to confirm the deletion 3 Press On Yes to
105. oll to Ignore Ignitor 3 Press On Yes to ignore the ignitor or Off No to enable the ignitor When Ignore Ignitor is set to True the GC does not try to light the flame using the ignitor The GC also completely ignores the Lit Offset setpoint and does not attempt autoignition This means that the GC cannot determine if the flame is lit and will not shut down the fuel gas Advanced User Guide Analog Out Fast peaks Advanced User Guide Configuration 3 The GC allows you to output analog data at two speeds The faster speed to be used only with the FID FPD and NPD allows minimum peak widths of 0 004 minutes 8 Hz bandwidth while the standard speed which can be used with all detectors allows minimum peak widths of 0 01 minutes 3 0 Hz bandwidth To use fast peaks 1 Press Config Analog Out 2 2 Scroll to Fast peaks and press On Yes The fast peaks feature does not apply to digital output If you are using the fast peaks feature your integrator must be fast enough to process data coming from the GC Integrator bandwidth should be at least 15 Hz 33 3 Configuration Valve Box See Unconfigured on page 25 and Ignore Ready page 24 on The valve box mounts on top of the column oven It may contain up to two valves mounted on heated blocks The block can accommodate two valves Valve positions on the blocks are numbered We suggest that valves be installed in the blocks in
106. olvent vial with diffusion cap filled with isooctane and inserted in Solvent A injector position Replace consumable parts liner septum traps syringe and so forth as needed for the checkout See To Prepare for Chromatographic Checkout Install the evaluation column See the procedure for the SS or PP in the Maintenance manual Bake out the evaluation column for at least 30 min at 180 C See the procedure for the SS or PP in the Maintenance manual Be sure to configure the column Check the FID baseline output The output should be between 5 pA and 20 pA and relatively stable If using a gas generator or ultra pure gas the signal may stabilize below 5 pA If the output is outside this range or unstable resolve this problem before continuing If the output is too low Check that the electrometer is on Advanced User Guide Advanced User Guide Chromatographic Checkout 5 Check that the flame is lit To light the FID flame on page 143 7 Create or load a method with the parameter values listed in Table 3 Table 3 FID Checkout Conditions Column and sample Type Sample Column flow Column mode Split splitless inlet Temperature Mode Purge flow Purge time Gas saver Packed column inlet Temperature Detector Temperature H3 flow Air flow Makeup flow N3 Lit offset Oven Initial temp Initial time Rate 1 Final temp Final time ALS settings if installed HP 5
107. omatically placed in order by execution time Editing events in the run table Advanced User Guide Press Run Table Move the cursor to the event you want to change To edit the time for an event move the cursor to the line labeled Time Type the desired time and press Enter 16 2 Programming 4 To edit a setpoint value scroll to the setpoint line Press On Yes or Off No or enter a numeric value for the setpoint Press Enter Deleting run time events 1 Press Run Table 2 From within this table press Delete to delete events from the run time table You will be asked to confirm the deletion 3 Press On Yes to delete the current timed event press Off No to cancel this operation 4 To delete the entire table press Delete Run Table Advanced User Guide Programming 2 Clock Time Programming Clock time programming allows certain setpoints to change automatically at a specified time during a 24 hour day Thus an event programmed to occur at 14 35 hours will occur at 2 35 in the afternoon A running analysis or sequence has precedence over any clock table events occurring during this time Such events are not executed Possible clock time events include e Valve control e Method and sequence loading e Starting sequences e Initiating blank and prep runs e Column compensation changes e Adjustments of the detector offset Using clock time events The Clock Table function allows you t
108. ombined flow 7 Turn on the filament Allow about 30 minutes for thermal stabilization A longer period may be needed for the highest sensitivity 8 If necessary turn Negative polarity On Yes to invert negative going peaks When a sample contains components giving both positive and negative going peaks Negative polarity can be switched on and off during a run as a timetable event Example Packed mode packed and large capillary columns Column flow is 15 to 60 mL min Set the reference flow to 1 5 times the sum of column flow makeup flow Makeup gas is recommended with all capillary columns It allows the column to be inserted all the way into the detector and withdrawn 1 mm If makeup is not used the column must be no more than 3 mm above the ferrule Minimum makeup flow is 1 mL min 1 8 inch stainless steel column If column flow is 30 mL min set the reference flow to 30 x 1 5 45 mL min Total detector flow is 30 45 75 mL min 10m x 0 53 mm column If column flow is 15 mL min and makeup flow 2 mL min set the reference flow to 1 5 x 15 2 25 5 mL min Total detector flow is 17 25 5 42 5 mL min Advanced User Guide Advanced User Guide Detectors 10 Example Capillary mode small capillary columns If combined column plus makeup flow is between 5 and 10 mL min set the reference flow at 3x the combined flow For a combined flow between 10 and 15 mL min use a multiplier of 2 This will bring th
109. ons and connections between flow modules and inlets detectors WARNING Hydrogen H3 is flammable and is an explosion hazard when mixed with air in an enclosed space for example a flow meter Purge flowmeters with inert gas as needed Always measure gases individually Always turn off detectors to prevent flame bead autoignition WARNING Hazardous sample gases may be present 1 Gather the following Electronic leak detector capable of detecting the gas type 7 16 9 16 and 1 4 inch wrenches for tightening Swagelok and column fittings 2 Check any potential leak points associated with any maintenance recently performed 3 Check GC fittings and connections that undergo thermal cycling since thermal cycling tends to loosen some fitting types Use the electronic leak detector to determine if a fitting is leaking Start by checking any newly made connections Remember to check connections in the gas supply lines after changing traps or supply cylinders Advanced User Guide 91 7 Checking for Leaks To Check for External Leaks Check for leaks at these connections mre O 5 5 k D ea e Gas su
110. or Off No to end the sequence Press Enter The active method 0 will change during the sequence if the subsequences use stored methods Therefore method 0 should be chosen for the priority sequence only if all subsequences use method 0 Press Mode Type and select the injector type Program the ALS subsequence See To program an ALS subsequence on page 85 Store the completed sequence See To save a sequence on page 86 Once a priority subsequence exists in a sequence you can activate it when the urgent samples are ready to be processed by 1 2 Press Seq Press again if necessary to display subsequence information Scroll to Use Priority and press On Yes When the priority samples are completed the normal sequence resumes 84 Advanced User Guide Methods and Sequences 6 To program an ALS subsequence 1 See step 1 through step 3 of To program a sequence on page 83 2 Press Mode Type and select the injector type 3 Enter injector sequence parameters Number of Injections vial the number of repeat runs from each vial Enter 0 if no samples are to be injected Samples the range first last of sample vials to be analyzed 4 Proceed with step 5 of To program a sequence on page 83 To program a valve subsequence 1 See step 1 through step 3 of To program a sequence on page 83 2 Press Mode Type and select Valve 3 Enter the valve sequence parameters
111. ou cannot change the data rate during a run You will see higher relative noise at the faster sampling rates Doubling the data rate can double peak height while the relative noise increases by 40 Although noise increases the signal to noise ratio is better at the faster rates This benefit only occurs if the original rate was too low leading to peak broadening and reduced resolution We suggest that rates be chosen so that the product of data rate and peak width in seconds is about 10 to 20 The figure shows the relationship between relative noise and data rates Noise decreases as the data rate decreases until you get to data rates of around 5 Hz As the sampling rate slows other factors such as thermal noise increase noise levels Advanced User Guide GC Output Signals 13 Relative noise level Excess noise due to flow oven temperature detector block temperatures etc 200 100 50 20 10 5 2 1 0 50 0 20 0 10 Faster data rates Slower data rates Zero Init Data Files This feature applies to digital output only and is mainly intended for non Agilent data systems It may help systems that have trouble with non zero baseline output When you turn it On the GC immediately begins to subtract the current detector output value s from any future values For example if you turn it on when the output is 20 pA the GC subtracts 20 pA from the digital output until you turn Zero Init Data Files Off You will not see any
112. ow path of the carrier gas Only configure columns that are in current use in your GC s carrier gas flow path Unused columns configured with the same pressure control device as a column in the current flow path cause incorrect flow results It is possible and sometimes appropriate to configure both installed columns to the same inlet Some pneumatic setpoints change with oven temperature because of changes in column resistance and in gas viscosity This may confuse users who observe pneumatics setpoints changing when their oven temperature changes However the flow condition in the column remains as specified by the column mode constant flow or pressure ramped flow or pressure and the initial setpoint values To view a summary of column connections To view a summary of column connections press Config Col then press Enter The GC lists the column connections for example Front Inlet gt Column 1 Column 1 gt Front detector Advanced User Guide Configuration 3 Front Detector Back Detector See Ignore Ready and Unconfigured on page 25 To configure the makeup reference gas The makeup gas line of your detector parameter list changes depending on your instrument configuration If you have an inlet with the column not defined the makeup flow is constant If you are operating with column defined you have a choice of two makeup gas modes See About Makeup Gas on page 140 for details 1 Pr
113. ow is available 13 Monitor the offset adjustment process a If Auto Adjust is On the adjust offset process starts automatically when the detector reaches setpoint If Auto Adjust is Off the Bead Voltage will gradually go to the last setpoint after the bead reaches setpoint temperature and the Dry Bead time has elapsed b If you need to set a new target offset enter an Adjust offset value Adjust offset starts when the detector reaches setpoint c If Auto Adjustis Off you can manually start the Adjust offset process by scrolling to Adjust offset then pressing On Yes d If your standard operating procedures require that you set the bead voltage directly see Setting NPD bead voltage manually optional on page 169 Selecting an NPD bead type Two beads are available Table 27 NPD beads Bead type Part number Advantages Disadvantages White ceramic G1534 60570 Standard Phosphorus tails Black ceramic 5183 2007 Durable no Lower nitrogen phosphorus sensitivity tailing about 40 Ceramic beads 164 Advanced User Guide Detectors 10 Selecting an NPD jet Open the oven door and locate the column connection fitting at the base of the detector It will look like either a capillary optimized fitting or an adaptable fitting Capillary optimized fitting Adaptable fitting Detector fitting __ L 5 Adapter e If you have an application that tends to clog the jet select
114. perform one run using the loaded checkout method Make sure that the data system will output a chromatogram Start the run If performing an injection using an autosampler start the run using the data system or press Start on the GC If performing a manual injection with or without a data system a Press Prep Run to prepare the inlet for splitless injection b When the GC becomes ready inject 1 uL of the checkout sample and press Start on the GC The following chromatogram shows typical results for a new detector with new consumable parts installed 75 5 Chromatographic Checkout FPD1 A 65_P1 SIG10014 D L_ FPD2B 65 _P1 SIG10014 D 150 pA 6000 5 5000 5 4000 3000 5 2000 Isooctane 1000 4 ot 7 co 4 mM i _ o4 8 Methylparathion 76 Sulfur performance 13 Install the sulfur filter and filter spacer 14 Make the following method parameter changes Table 8 Sulfur method parameters S Parameter Value mL min H3 flow 50 Air flow 60 15 Ignite the FPD flame if not lit 16 Display the signal output and monitor This output typically runs between 50 and 60 but can be as high as 70 Wait for the output to level off This takes approximately 1 hour If the baseline output is too high Check column installation If installed high the stationery phase burns out and increases measured output Check for leaks Bake out the detector and column at 2
115. plit Splitless Inlet 114 Split Splitless inlet split mode overview 114 Split Splitless inlet splitless mode overview 115 The S SL inlet pulsed split and splitless modes 116 Split Splitless inlet split mode minimum operating pressures 117 Selecting the correct S SL inlet liner 118 Vapor Volume Calculator 120 Selecting parameters for the S SL splitless mode 121 Ee Agilent Technologies 105 Inlets Using Hydrogen 106 When using hydrogen H3 as the carrier gas be aware that hydrogen H3 gas can flow into the oven and create an explosion hazard Therefore be sure that the supply is off until all connections are made and ensure that the inlet and detector column fittings are either connected to a column or capped at all times when hydrogen H3 gas is supplied to the instrument Hydrogen H is flammable Leaks when confined in an enclosed space may Create a fire or explosion hazard In any application using hydrogen H3 leak test all connections lines and valves before operating the instrument Always turn off the hydrogen H2 supply at its source before working on the instrument Advanced User Guide Inlets 8 Inlet Overview Table 10 Comparing inlets Sample Sample Inlet Column Mode concentration Comments to column Split splitless Capillary Split High Very little Pulsed split High Useful with large Very little injections Splitless Low All Pulsed splitless Low Useful with large All injections Packed column
116. points compiled from the active parameter lists on the instrument This is a quick way to view active setpoints during a run without having to open multiple lists To configure the setpoint status table You can change the order of the list You might want the three most important setpoints to appear in the window when you open the table 1 Press Config Status 2 Scroll to the setpoint that should appear first and press Enter This setpoint will now appear at the top of the list 3 Scroll to the setpoint that should appear second and press Enter This setpoint will now be the second item on the list 4 And so on until the list is in the order you wish Advanced User Guide Time Configuration Press Time to open this function The first line always displays the current date and time and the last line always displays a stopwatch The two middle lines vary Betweenruns Show last and next calculated run times Duringarun Show time elapsed and time remaining in the run During Post Run Show last run time and remaining Post Run time To set time and date 1 Press Config Time 2 Select Time zone hhmm and enter the local time offset from GMT using a 24 hour format 3 Select Time hhmm and enter the local time 4 Select Date ddmmyy and enter the date To use the stopwatch Advanced User Guide 1 Press Time Scroll to the time line To begin the timed period press Enter To stop the tim
117. pply bulkhead fittings e Gas cylinder fitting e Regulator fittings e Traps e Shut off valves e T fittings Perform a pressure drop test 1 Turn off the GC 2 Set the regulator pressure to 415 kPa 60 psi 3 Fully turn the regulator knob counterclockwise to shut the valve 4 Wait 5 minutes If there is a measurable drop in pressure there is a leak in the external connections No drop in pressure indicates that the external connections are not leaking 92 Advanced User Guide Checking for Leaks 7 To Check for GC Leaks Check for leaks at these connections e Inlet septum septum head liner split vent trap split vent trap line and purge vent fittings e Column connections to inlets detectors valves splitters and unions e Fittings from the flow modules to the inlets detectors and valves e Column adapters e Agilent capillary flow fittings Advanced User Guide 93 7 Checking for Leaks To Perform a SS Inlet Pressure Decay Test 94 The pressure decay test checks for leaks from the inlet flow module up to the column fitting After performing maintenance first check for leaks in externally accessible areas See To Check for External Leaks If a leak is known to exist check the externally accessible inlet fittings first especially any connection that has seen recent maintenance such as the septum nut column adapter column connection and so forth The pressure decay leak test descri
118. pressure at the Inlet end of the column the device controlling the pressure at the column Outlet and the Thermal zone that controls its temperature With this information the instrument can calculate the flow through the column This has great advantages when using capillary columns because it becomes possible to e Enter split ratios directly and have the instrument calculate and set the appropriate flow rates e Enter flow rate or head pressure or average linear velocity The instrument calculates the pressure needed to achieve the flow rate or velocity sets that and reports all three values Split splitless inlet only e Perform splitless injections with no need to measure gas flows e Choose any column mode If the column is not defined your choices are limited Advanced User Guide Advanced User Guide Configuration 3 Except for the simplest configurations such as a column connected to a specific inlet and detector we recommend that you begin by making a sketch of how the column will be connected 1 Press Config Col then enter the number of the column to be configured Scroll to the Length line type the column length in meters followed by Enter Scroll to Diameter type the column inside diameter in microns followed by Enter Scroll to Film thickness type the film thickness in microns followed by Enter The column is now defined If you do not know the column dimensions they are u
119. pressure sensors in all modules 1 Press Service Mode scroll to Diagnostics and press Enter Scroll to Electronics and press Enter Scroll to Pneumatics and press Enter FP Ww N Scroll to Zero all pressure sensors and press Info The GC will remind you that all gas supplies must be disconnected at the back panel Turning them off is not adequate the valves may leak 5 Press On Yes to zero or Clear to cancel Column calibration Advanced User Guide As you use a capillary column you may occasionally trim off portions changing the column length If measuring the actual length is impractical and if you are using EPC with a defined column you can use an internal calibration routine to estimate the actual column length Similarly if you do not know the column internal diameter or believe it is inaccurate you can estimate the diameter from related measurements Before you can calibrate the column make sure that e You are using a capillary column e The column is defined e There are no oven ramps e The column gas source usually the inlet is On and non zero Also note that column calibration fails if the calculated column length correction is gt 5 m or if the calculated diameter correction is gt 20 um Calibration modes There are three ways to calibrate the column length and or diameter e Calibrate using an actual measured column flow rate e Calibrate using an unretained peak time elution tim
120. quired for shorter wide bore columns The minimum pressure is a function of carrier gas type total inlet flow liner design and possible contamination of the split vent tube or trap A wide bore column requires a much lower inlet pressure than a typical capillary column to maintain a given flow Setting the split ratio total flow too high when using a wide bore column can create an unstable control relationship between the pressure and flow control loops Advanced User Guide 117 8 inlets Table 13 Approximate minimum viable inlet pressures for split splitless inlet in split mode in psi kPa Split vent flow mL min 50 100 100 200 200 400 400 600 Helium and hydrogen carrier gases Split liners 5183 4647 19251 60540 2 5 17 2 3 5 24 1 4 5 31 6 0 41 4 Splitless liners 5062 3587 5181 8818 4 0 27 6 5 5 37 9 8 0 55 2 11 0 75 4 Nitrogen carrier gas Split liners 19251 60540 5183 4647 Splitless liners 5062 3587 5181 8818 3 0 20 7 4 0 27 6 4 0 27 6 6 0 41 4 These numbers are based on the resistance to flow of new clean inlet systems Sample condensation in the split vent tube or a dirty filter can make these values non attainable Selecting the correct S SL inlet liner Table 14 Split mode liners Split liner A good liner for split mode operation will offer very little restriction to the split flow path between the bottom of the liner and the inlet gold seal and between the o
121. r between 500000 and 500000 A value smaller than the current Zero shifts baseline up Range Scales data coming from the detector Range is also referred to as gain scaling or sizing It sizes the data coming from the detector to the analog signal circuits to avoid overloading the circuits clamping Range scales all analog signals If a chromatogram looks like A or B in the next figure the data needs to be scaled as in C so that all peaks are visible on the paper Valid setpoints are from 0 to 13 and represent 20 1 to ge 8192 Changing a setpoint by 1 changes the height of the chromatogram by a factor of 2 The following chromatograms illustrate this Use the smallest possible value to minimize integration error 197 13 GC Output Signals 198 A Range 0 Akili B Range 3 T Te Range 1 There are limits to usable range settings for some detectors The table lists the valid range setpoints by detector Table 37 Range limits Detector Usable range settings 2 FID 0 to 13 NPD 0 to 13 FPD 0 to 13 TCD 0to6 vECD 0to6 Analog input Oto7 Range may be run time programmed See Run Time Programming on page 14 for details Analog data rates Your integrator or recorder must be fast enough to process data coming from the GC If it cannot keep up with the GC the data may be damaged This usually shows up as broadened peaks and loss of resolution Speed is
122. range C 100 V oven 200 220 230 240 V ramp rate C minute oven ramp rate C minute 50 to 70 30 75 70 to 115 30 45 115 to 175 30 40 175 to 300 30 30 300 to 425 20 20 Setting the oven parameters for constant temperature Advanced User Guide An isothermal run is one in which the oven is maintained at a constant temperature For an isothermal run set Rate1 to zero 1 Press Oven to open the oven parameter list 2 Enter the oven temperature for the isothermal run 3 Enter the number of minutes Initial time that you want the oven to stay at this temperature This time is the duration of the run 131 9 Columns and Oven 4 If Rate1 is not already 0 enter zero for an isothermal run Setting the oven parameters for ramped temperature Single ramp 1 2 3 Press Oven to open the oven parameter list Enter a starting temperature Temperature Enter the time Initial time that you want the oven to stay at Temperature Enter the rate Rate 1 at which the oven temperature is to change Enter the final temperature Final temperature 1 Enter the time Final time 1 the oven is to hold Final temperature 1 To end the oven ramp program after Ramp 1 set Rate2 to Zero Multiple ramps In a multiple ramp program Final time for one ramp is also Initial time for the next ramp Thus there is only one Initial time 1 2 132 Set up the first oven ramp as described in Single ramp
123. rating method Advanced User Guide 97 7 Checking for Leaks To Correct Leaks in the Split Splitless Inlet 98 If the inlet fails a pressure decay test check the following Check the caps plugs used in the test make sure each is correctly installed and tight If you performed the leak test after performing maintenance check for proper installation of the part s handled during the maintenance Check the tightness of the septum nut See To change the septum on the split Splitless inlet Check the septum Replace if old or damaged Check the insert assembly installation Check the liner and liner O ring See To change the liner and O ring on the split splitless inlet If you changed the gold seal verify correct installation See To replace the gold seal on the split splitless inlet Make sure the inlet temperature remained constant during the test If these items do not resolve the problem contact Agilent for service Advanced User Guide Checking for Leaks 7 To Perform a PP Inlet Pressure Decay Test The pressure decay test checks for leaks from the inlet flow module up to the column fitting After performing maintenance first check for leaks in externally accessible areas See To Check for External Leaks If a leak is known to exist check the externally accessible inlet fittings first especially any connection that has seen recent maintenance such as the septum nut column adapter column co
124. rature to 70 C Enter a pressure setpoint of 25 psi 172 kPa Make sure that the pressure supplied to the GC is at least 10 psi 70 kPa higher than the inlet pressure If pressure cannot be achieved there is either a large leak or the supply pressure is too low Allow the inlet temperature to stabilize Temperature changes can invalidate the test Cap the septum purge fitting with the ECD TCD detector plug 95 7 Checking for Leaks Back inlet split vent Front inlet split vent Back inlet purge vent Front inlet purge vent lt Front purge vent shown plugged 14 Press Front or Back Inlet Scroll to Pressure and press Off No 15 Quickly turn off the carrier gas supply at its source 16 Monitor the pressure for 10 minutes Use the timer by pressing Time and Enter A pressure drop of less than 0 5 psig 0 05 psi min or less 3 4 kPa or 0 34 kPa min is acceptable 96 Advanced User Guide Checking for Leaks 7 If the pressure drops much faster than the acceptable rate see To Correct Leaks in the Split Splitless Inlet Retest Note that liner size impacts pressure drop An inlet with a smaller volume liner does not tolerate as large a leak rate as an inlet with a larger volume liner 17 After the inlet passes the test restore the GC to operating condition Remove any caps plugs Reinstall the column Restore the correct column configuration Load the ope
125. re Ready on page 24 A pressure control module PCM provides one channel of gas control This channel is a simple forward pressure regulator that maintains a constant pressure at its output With a fixed downstream restrictor it provides constant flow To assign a GC communication source to a PCM 1 Unlock the GC configuration press Options select Keyboard amp Display and press Enter Scroll down to Hard Configuration Lock and press Off No 2 Press Config scroll to a PCMx and press Enter 3 With Unconfigured selected press Mode Type select Install EPCx and press Enter 4 When prompted by the GC turn the power off then on again To configure the other parameters on this PCM see To configure a PCM To configure a PCM Advanced User Guide 1 Press Config scroll to the PCMx and press Enter 2 Scroll to Gastype press Mode Type make a selection and press Enter The pressure control mode is set by pressing PCM Select Mode press Mode Type select the mode and press Enter 37 3 3 Configuration Status 38 The Status key has two tables associated with it You switch between them by pressing the key The Ready Not Ready status table This table lists parameters that are Not Ready or gives you a Ready for Injection display If there are any faults warnings or method mismatches present they are displayed here The setpoint status table This table lists set
126. rs 170 New beads After a new bead reaches the initial voltage begin to increase the voltage value in 0 05 V increments until the bead ignites Wait about 10 seconds between each voltage adjustment Monitor the detector output When the bead ignites the output will rise suddenly then decrease towards a more stable value It is best to allow the NPD to remain in this state without further adjustment for about 24 hours Then you may adjust the bead voltage in small increments 0 05 to 0 1 V until reaching the desired offset With a clean environment clean gas supplies and low bleed column a typical offset may decrease 6 12 pA during a 24 hour period Typical voltages for new ceramic beads range from 2 5 to 3 7 volts Higher values reduce bead life Advanced User Guide About the FPD Makeup Q PS Pressure Sensor Advanced User Guide Detectors 10 The sample burns in a hydrogen rich flame where some species are reduced and excited The gas flow moves the excited species to a cooler emission zone above the flame where they decay and emit light A narrow bandpass filter selects light unique to one species while a shield prevents intense carbon emission from reaching the photomultiplier tube PMT The light strikes a photosensitive surface in the PMT where a light photon knocks loose an electron The electron is amplified inside the PMT for an overall gain of up to a million Vent Emission Zone
127. rsus concentration curve is linear for four orders of magnitude or more linear dynamic range 104 or higher for a broad range of compounds You should still run a calibration curve on your samples to find the limits of the linear range for your materials uECD detector gas The uECD operates with either nitrogen or argon methane as the makeup and anode gas Purity is critical gases must exceed 99 9995 purity Because of the high detector sensitivity carrier and makeup gas must be dry and oxygen free Moisture chemical and oxygen traps in good condition should be installed in carrier and makeup gas supply lines Do not use plastic including PTFE tubing plastic bodied traps or O ring seals Advanced User Guide 157 10 Detectors 158 uECD temperature To prevent peak tailing and to keep the cell clean the detector temperature should be set higher than the highest oven temperature used the setpoint should be based on the elution temperature of the last compound If you operate at excessively high temperatures your results will not necessarily improve and you may increase sample and column decomposition uECD analog output If you intend to use the analog output from the uECD you must set the output Range to 10 1 Press Analog Out 1 or Analog Out 2 2 Scroll to Range 3 Type 10 and press Enter Recommended starting conditions for new uECD methods Use the following information when selecting temperatures
128. s When using packed columns we recommend a small makeup gas flow 2 to 3 mL min to get the best peak shapes Use the next figure to select a value for reference gas flow for either capillary or packed columns Any ratio within 0 25 of that in the figure is suitable 148 Advanced User Guide Detectors 10 4 0 3 0 Ratio of reference flow to column makeup flow 2 0 1 0 0 T T 10 20 30 40 50 60 Column makeup flow mL min TCD gas pressures Choose a flow find a pressure set source pressure 10 psi 70 kPa higher Reference gas flow mL min Pressure psig 10 20 30 40 50 60 kPa 69 138 207 276 345 414 Advanced User Guide 149 10 Detectors Makeup gas flow mL min Pressure psig kPa 69 138 207 276 345 414 Selecting reference and makeup flows for the TCD Table 23 Recommended flow rates and temperatures Gas type Flow range Carrier gas Packed 10 to 60 mL min hydrogen helium nitrogen Capillary 1 to 5 mL min Reference 15 to 60 mL min same gas type as carrier See the figures to select a value Capillary makeup 5 to 15 mL min capillary columns same gas type as carrier 2 to 3 mL min packed columns Detector temperature lt 150 C cannot turn on filament Detector temperature should be 30 C to 50 C greater than highest oven ramp temperature Sample components with hig
129. ss Prep Run see Pre Run and Prep Run on page 110 before manually injecting a sample Setting parameters for the S SL pulsed modes The pulsed mode parameters are the same as the non pulsed parameters but with two additional values Pulsed pressure The inlet pressure you want at the start of the run The pressure rises to this value when Prep Run is pressed and remains constant until Pulse time elapses when it returns to Pressure Pulse time This is the time after the start of the run when the inlet pressure returns to Pressure Pre Run and Prep Run on page 110 Pre Run and Prep Run on page 110 Pre Run and Prep Run on page 110 Pre Run and Prep Run on page 110The preferred technique for concentrating analytes in the inlet liner is to use a single large volume injection Using a high capacity syringe and one septum puncture reduces the possibility of contamination and generally improves results when compared against a multiple septum puncture technique However if needed you can perform multiple septum punctures during the vent time This technique requires an Agilent data system and automatic liquid sampler The configured syringe size changes the available choices for injection volume Injection volume Select the injection volume then enter a number of injections The total injection volume will be displayed Preinjection washes and pumps are performed only before the first injection of a m
130. ss Time again to view the stopwatch display 207 14 Miscellaneous Topics Service Mode The Service Mode key presents the Service Reminders and other functions Service Reminders Internal counters This is a set of 12 counters that monitor the use of various items on the GC such as syringes septa and columns These counters only count runs and their definitions are fixed You can set limits for each item when a limit is reached the Service Due light on the status board comes on Examine the limits to identify the item that has reached its limit You may enter a limit for each item reset a count to 0 by pressing Off No or disable a counter by entering a limit of The counter limits in Table 39 are recommendations Adjust the limits as needed to fit your needs Table 39 Recommended initial counter limits Counter Recommended Limit Syringe 1 and 2 Septum Front and Back Liner Front and Back Columns 1 6 1000 injections 150 injections for 7693A ALS 2000 injections if using the Merlin Micro Seal Sample and method dependent Depending on the sample type the liner may need to be replaced daily weekly or monthly In some cases septum chunks get in the liner You may want to match the septum counter or set the liner counter to a multiple of 2 or 3 times the septum counter Sample and method dependent Depending on the sample type columns may need to be replaced after 50 injections or they may
131. stem Data rate 8 0 0 0 Normal 0 20 0 6000 Tul 5 Hz 6 Display the signal output A stable output at any value between 12 5 and 750 uV inclusive is acceptable If the baseline output is lt 0 5 display units lt 12 5 uV verify that the detector filament is on If the offset is still lt 0 5 display units lt 12 5 uV your detector requires service If baseline output is gt 30 display units gt 750 uV there may be chemical contamination contributing to the signal Bakeout the TCD If repeated cleanings do not give an acceptable signal check gas purity Use higher purity gases and or install traps 7 If using a data system prepare the data system to perform one run using the loaded checkout method Make sure that the data system will output a chromatogram 8 Start the run If performing an injection using an autosampler start the run using the data system or press Start on the GC Advanced User Guide Chromatographic Checkout 5 If performing a manual injection with or without a data system a Press Prep Run to prepare the inlet for splitless injection b When the GC becomes ready inject 1 uL of the checkout sample and press Start on the GC 9 The following chromatogram shows typical results for a new detector with new consumable parts installed 25 uV 70 C14 C15 C16 60 50 40 30 20 T T T T T T T T T T T T T T T T T T Time min Advanced User Gu
132. sually supplied with the column or if you do not wish to use the GC calculating features enter 0 for either Length or Diameter The column will be not defined Scroll to Inlet Press Mode Type to select a gas pressure control device for this end of the column Selections include the installed GC inlets and installed PCM channels Select the appropriate gas pressure control device and press Enter Scroll to Outlet Press Mode Type to select a gas pressure control device for this end of the column When a detector is selected the outlet end of the column is controlled at 0 psig for the FID TCD FPD NPD and uECD or vacuum for the MSD Select the appropriate gas pressure control device and press Enter Scroll to Thermal zone Press Mode Type to see the available choices In most cases this will be GC oven but you may have an MSD transfer line heated by an auxiliary zone valves in a separately heated valve box or other configurations Select the appropriate Thermal zone and press Enter This completes configuration for a single capillary column Additional notes on column configuration Packed columns should be configured as column not defined To do this enter 0 for either column length or column diameter 29 3 30 Configuration You should check configurations for all columns to verify that they specify the correct pressure control device at each end The GC uses this information to determine the fl
133. t a sequence When a sequence is aborted it stops immediately without waiting for the current run to finish These actions will cause a sequence to abort e A run is stopped by pressing Stop e A sampler error occurs producing an error message e The GC detects a configuration mismatch during a method load e A running sequence tries to load an empty method e The sampler is turned off You can correct the problem and then resume the sequence The aborted sample run will be repeated Advanced User Guide 87 6 Methods and Sequences 88 Advanced User Guide Agilent 7820A Gas Chromatograph Advanced User Guide 7 Checking for Leaks Preparing the GC for Maintenance 90 To Check for External Leaks 92 To Check for GC Leaks 93 To Perform a SS Inlet Pressure Decay Test 94 To Correct Leaks in the Split Splitless Inlet 98 To Perform a PP Inlet Pressure Decay Test 99 To Correct Leaks in the Packed Column Inlet 103 Ee Agilent Technologies 89 7 Checking for Leaks Preparing the GC for Maintenance 90 Before most maintenance procedures the GC must be made ready The purpose of this preparation is to avoid damage to both the instrument electronics columns etc and the user shocks burns Column and oven preparation The main hazards here are temperature burns and column exposure to air e Cool the oven by changing its setpoint to 35 C This allows the oven fan to assist cooling e Leave the carri
134. t is sensed by an electrometer converted to digital form and sent to an output device F Vent a Electrically heated bead t PS Pressure Sensor Column 160 Advanced User Guide Detectors 10 NPD flow temperature and bead recommendations Advanced User Guide Table 26 General operating values Gas or Setting Recommendation Carrier gas helium hydrogen nitrogen Capillary choose optimum flow based on column dimensions Detector gases Hydrogen Ceramic bead 2 to 5 mL min Air Ceramic bead 60 mL min Capillary makeup helium nitrogen Ceramic bead Nitrogen 5 to 10 mL min Helium less than 5 mL min Temperature Default is 250 C operating range is 150 C to 400 C e lt 150 C the Adjust offset process will not start e 325 to 335 C is recommended e Detector temperature should be greater than the highest oven temperature With higher detector temperatures less bead heating voltage is required Adjust offset Default is 30 pA suggested operating range is 20 to 40 pA and allowable range is 0 to 99 9 pA e gt 50 pA increases sensitivity but reduces bead life e Lower settings reduce sensitivity and increase bead life but settings too low will result in solvent quenching e The time required for Adjust offset depends on the bead type and condition Bead voltage Ceramic bead Range is 0 to 4 095 V e Use Auto Adjust On Dry Bead and let the GC set the Bead Voltage for you
135. t on the clock table 168 Aborting NPD adjust offset 168 Extending the NPD bead life 168 Setting the initial bead voltage for new beads 169 Setting NPD bead voltage manually optional 169 Aboutthe FPD 171 FPD linearity 172 FPD Lit Offset 172 Starting Up and Shutting Down the FPD 172 FPD photomultiplier protection 172 FPD optical filters 172 Inlet liners for use with the FPD 173 FPD temperature considerations 173 FPD gas purity 173 FPD gas flows 173 Lighting the FPD flame 174 Setting parameters for the FPD 175 The Valve Box 178 Heating the valves 178 Valve temperature programming 178 Valve Control 179 The valve drivers 179 The internal valve drivers 179 Valve Types 181 Configuring a Valve 182 Controlling a Valve 183 From the keyboard 183 From the run or clock time tables 183 Advanced User Guide 12 Cables Gas sampling valve 183 About Cables and Back Panel Connectors 186 Back panel connectors 186 Sampler connectors 186 Signal connector 186 REMOTEconnector 187 TEST PORT connector 187 LAN connector 187 Using the Remote Start Stop cable 188 Connecting Agilent products 188 Connecting non Agilent products 188 Connecting Cables 191 Cable Diagrams 193 Analog cable general use 193 Remote start stop cable 193 13 GC Output Signals About Signals 196 Analog Signals 197 Analog zero 197 Analogrange 197 Analog data rates 198 Selecting fast peaks analog output 199 Digital Signals 200 Digital zero 200 Signal
136. t with using helium as carrier but causes reduced sensitivity to components other than hydrogen e Operate the detector at higher temperatures from 200 C to 300 C You can find the correct detector operating temperature by analyzing a known range of hydrogen concentrations increasing the operating temperature until the hydrogen peak exhibits normal shape and is always in the same direction negative relative to normal response to air or propane regardless of concentration This temperature also ensures high sensitivity and linear dynamic range Because hydrogen peaks are negative you must turn negative polarity on at appropriate times so the peak appears positive Advanced User Guide 151 10 Detectors 152 Setting parameters for the TCD 1 Press Front Det or Back Det 2 Set the detector temperature Do not set higher than the maximum temperature allowed for the column because part of the column passes through the heated block and into the cell 3 Verify that makeup gas type is the same as that plumbed to your instrument next to Makeup line in the parameter list Change the gas type if necessary 4 Set the reference gas flow rate 5 If you are using packed columns turn off the makeup gas or proceed to step 6 and enter 2 to 3 mL min see TCD carrier reference and makeup gas on page 148 and proceed to step 7 6 If you are using capillary columns choose a flow mode and set the makeup gas flow or c
137. ta system such as ChemStation or EZChrom See Table 36 for the conversions from units shown on the GC display to units as shown in Agilent data systems and integrators Table 36 Signal conversions Signal type 1 display unit is equivalent to Detector FID NPD 1 0 pA 1 0 x 1012 A TCD 25 uV 2 5 x 10 V ECD 1 Hz Analog input board use to connectthe 15 pV GC to non Agilent detector Nondetector Thermal 1 C Pneumatic Flow 1 mL min Pressure 1 pressure unit psi bar or kPa Diagnostic Mixed some unscaled Advanced User Guide Analog Signals Analog zero Analog range Advanced User Guide GC Output Signals 13 If you use an analog recorder you may need to adjust the signal to make it more usable Zero and Range in the Signal parameter list do this Zero Subtracts value entered from baseline Press On Yes to set to current Value or Off No to cancel This is used to correct baseline elevation or offsets A common application is to correct a baseline shift that occurs as the result of a valve operation After zeroing the analog output signal is equal to the Value line of the parameter list minus the Zero setpoint Zero can be programmed as a run time event For details see Run Time Programming on page 14 1 Verify that the detector is on and in a ready state Press Analog Out Scroll to Zero FP WwW N Press On Yes to set Zero at the current signal value or Enter a numbe
138. temp Initial time Rate 1 Final temp Final time ALS settings if installed HP 5 30 m x 0 32 mm x 0 25 um 19091J 413 HECD checkout 18713 60040 or Japan 5183 0379 Constant flow 6 5 mL min helium 200 C Splitless 60 mL min 0 75 min 200 C 300 C 30 mL min constant makeup Should be lt 1000 display counts in Agilent ChemStation lt 1000 Hz 80 C 0 min 15 C min 180 C 10 min 69 5 70 Chromatographic Checkout Table 6 uECD Checkout Conditions continued Sample washes Sample pumps Sample wash volume Injection volume Syringe size Solvent A pre washes Solvent A post washes Solvent A wash volume Solvent B pre washes Solvent B post washes Solvent B wash volume Injection mode Airgap Volume Viscosity delay Inject Dispense Speed 7693A Prelnjection dwell PostInjection dwell Manual injection Injection volume Data system Data rate 2 6 8 Tul 10 uL co oOo O N N Normal 0 20 0 6000 1 uL 5 Hz 7 If using a data system prepare the data system to perform one run using the loaded checkout method Make sure that the data system will output a chromatogram 8 Start the run If performing an injection using an autosampler start the run using the data system or press Start on the GC If performing a manual injection with or without a data system a Press Prep Run to prepare the inlet for splitless injection b When the GC b
139. th a flame ionization detector The gas sample is separated on the column and passed over a heated catalyst in the presence of hydrogen which converts the CO and COs peaks to CH4 Sample Hydrogen Air Gas sample valve Column Nickel catalyst fip c m Nickel catalyst gas flows Advanced User Guide For a standard FID installation Table 19 Gas flows for a standard FID Gas Flow rate mL min Carrier helium 30 FID hydrogen 30 see Caution FID air 400 9 137 138 Columns and Oven Table 20 Gas flows for a TCD FID series installation Gas Flow rate mL min Carrier helium 30 TCD switching flow 25 FID hydrogen 45 see Caution FID air 500 CAUTION Hydrogen flow is pressure controlled where an FID provides a known resistance The nickel catalyst tube increases flow resistance so that the calibration is no longer valid You must measure hydrogen flow with a bubble or similar meter The nickel catalyst can be damaged by exposure to air Setting temperatures for the nickel catalyst tube The nickel catalyst tube is usually mounted in the back inlet position and controlled by the back inlet temperature setpoint For most analyses set these temperatures e Nickel catalyst tube 375 C e FID 400 C Advanced User Guide Agilent 7820A Gas Chromatograph Advanced User Guide 10 Detectors About Makeup Gas 140 About the FID 141 Aboutthe
140. thod but not the stored one Save the corrected method using the same number which overwrites the stored method or a new number which saves both versions of the method Advanced User Guide Creating Sequences Methods and Sequences 6 A sequence specifies the samples to be run and the stored method to be used for each The sequence is divided into a priority sequence ALS only subsequences each of which uses a single method and post sequence events e Priority sequence allows you to interrupt a running ALS or valve sequence to analyze urgent samples See About the priority sequence on page 83 e Subsequences contain the stored method number and information that defines a set of samples and calibrators to be analyzed using a particular method Sampler and or valve subsequences can be used in the same sequence e Post sequence names a method to be loaded and run after the last run in the last subsequence Specifies whether the sequence is to be repeated indefinitely or halted after the last subsequence Samples in each subsequence are specified as either ALS locations or sampling valve positions gas sampling valves Five sequences with up to five subsequences each can be stored About the priority sequence The priority sequence consists of a single sampler or valve subsequence and a special Use priority parameter which can be activated at any time even when a sequence is running This feature allows
141. tions select Keyboard amp Display and press Enter Scroll down to Hard Configuration Lock and press Off No The GC configuration remains unlocked until the GC is power cycled off and on The states of the various hardware elements are among the factors that determine whether the GC is Ready for analysis Under some circumstances you may not wish to have a specific element readiness considered in the GC readiness determination This parameter lets you make that choice The following elements allow readiness to be ignored inlets detectors the oven PCM and auxiliary EPC modules For example suppose an inlet heater is defective but you don t plan to use that inlet today By setting Ignore Ready TRUE for that inlet you can use the rest of the GC After the heater is repaired set Ignore Ready FALSE or the run could start before that inlet s conditions are ready To ignore an element s readiness press Config then select the element Scroll to Ignore Ready and press On Yes to set it to True To consider an element s readiness press Config then select the element Scroll to Ignore Ready and press Off No to set it to False Advanced User Guide Configuration 3 Information displays Below are some examples of configuration displays EPC1 INLET SS EPC 1 is used for an inlet of type split splitless It is not available for other uses EPC3 DET EPC FID EPC 3 is controlling detector
142. ultiple injection set Advanced User Guide 123 8 inlets About the Packed Column Inlet This inlet is also known as the purged packed inlet PP It is used with packed columns when high efficiency separations are not required It can also be used with wide bore capillary columns if flows greater than 10 mL min are acceptable The inlet is flow controlled regardless or whether or not the column is capillary and defined or packed Carrier Supply 80 PSI Septum Purge D d l zz aa EPC Module Frit Inlet Weldment PS Pressure Sensor Column FS Flow Sensor Setting parameters The inlet operates in flow control mode 124 Advanced User Guide Inlets 8 While in flow control mode you cannot enter pressures here Temperature The setpoint and actual temperature values Pressure The actual pressure in psi bar or kPa supplied to the inlet You cannot enter a setpoint here Total flow Enter your setpoint here actual value is displayed Inlet is mass flow controlled Advanced User Guide 125 8 inlets 126 Advanced User Guide Agilent 7820A Gas Chromatograph Advanced User Guide 9 Columns and Oven About the Oven 128 Oven safety 128 Configuring the Oven 129 About Oven Temperature Programming 130 Programming setpoints 130 Oven ramp rates 131 Setting the oven parameters for constant temperature 131 Setting the oven parameters for ramped temperature 132 Abo
143. ut Columns 133 Nickel Catalyst Tube 137 About the nickel catalyst tube 137 Nickel catalyst gas flows 137 Setting temperatures for the nickel catalyst tube 138 Ee Agilent Technologies 127 9 Columns and Oven About the Oven Oven safety 128 Table 17 Oven capabilities Capability Range Temperature range 0 C to the configured limit Maximum temperature 425 C 100 V oven 350 C Temperature programming Up to five ramps Maximum run time 999 99 minutes Temperature ramp rates 0 to 75 C min depending on instrument configuration 100 V oven 0 to 30 C min For safety opening the oven door turns off power to the oven heater and fan but maintains the setpoints in memory Closing the oven door returns the oven to normal operation If the oven cannot attain or maintain an entered setpoint temperature during normal above ambient operation a problem is assumed and the oven is switched off Possible problems include e The oven vent flaps not working e The oven fan heater or temperature sensor not working properly e An electronic problem When a shutdown occurs the Off line in the oven parameter list blinks and the oven remains off until switched on again by pressing Oven On or by editing the Temperature setpoint Advanced User Guide Configuring the Oven Advanced User Guide Columns and Oven 9 Oven configuration sets maximum temperature equilibration time and the cool down mode Ma
144. utside of the liner and the inside of the injection port body The preferred Agilent split liner part number 5183 4647 incorporates a glass positioning bead on the bottom to facilitate this It will also incorporate glass wool or some other source of surface area inside the liner that provides for complete sample vaporization across the boiling point range of the sample Select an appropriate liner from Table 14 Liner Description Volume Mode Deactivated Part Number lt Low Pressure Drop 870 uL Split Fast Yes 5183 4647 Positioning Bead Injection 4mm ID Glass Wool 990 uL Split Fast No 19251 60540 Injection A i m Empty Pin amp Cup 800 uL Split Manual No 18740 80190 Only EEr PackedPin amp Cup 800pL Split Manual No 18740 60840 Only 118 Advanced User Guide Table 15 Splitless mode liners Inlets Splitless liner The liner volume must contain the solvent vapor The liner should be deactivated to minimize sample breakdown during the purge delay Solvent vapor volume can be reduced by using Pulsed Splitless mode Use the Vapor Volume Calculator to determine vapor volume requirements Vapor volume lt 300 pL Use 2 mm liner 250 uL volume 5181 8818 or similar Vapor volume 225 300 pL Consider pulsed splitless mode to reduce vapor volume Vapor volume gt 300 pL Use 4 mm liner 5062 3587 or similar Vapor volume gt 800 pL Consider pulsed splitless mode to reduce vapor volume
145. ve a higher sulfur content which impairs sulfur detection in the compound being studied Instrument or Chromatographic grades work well Agilent recommends using helium carrier nitrogen makeup gas and air with 99 9995 purity or better Use carbon oxygen and moisture traps Select traps to remove sulfur compounds from detector air and nitrogen gases A helium getter is also recommended Table 30 gives the flows for the maximum sensitivity FPD flame which is hydrogen rich and oxygen poor Table 30 Recommended flows Sulfur mode flows Phosphorus mode mL min flows mL min Carrier hydrogen helium nitrogen argon Packed columns 10 to 60 10 to 60 Capillary columns 1to5 1to5 Detector gases 173 10 Detectors 174 Table 30 Recommended flows continued Sulfur mode flows Phosphorus mode mL min flows mL min Hydrogen 50 75 Air 60 100 Carrier makeup 60 60 Helium either as carrier or makeup gas may cool the detector gases below the ignition temperature We recommend using nitrogen rather than helium Lighting the FPD flame Before trying to light the flame have the detector at operating temperature Removing the condensate tubing may help but be sure to replace it before making runs It is difficult to light the flame with the flows shown in Table 30 particularly in the sulfur mode If the flame will not light with the sulfur mode flows shown change to the phosphorus mode flows After ignition gradu
146. when the bead reaches the temperature setpoint after having been turned off or cooled below 150 C Auto adjust starts after Dry Bead hold time if enabled Auto Adjust Bead uses the adjust offset feature to protect the bead especially new beads by making sure that the desired offset is obtained with the lowest possible bead voltage When Off the bead voltage will rise as soon as the Dry Bead time elapses or as soon as the temperature setpoint is reached if Dry Bead is off Dry Bead Recommended On When On the bead temperature holds at 150 C for 5 minutes before continuing to the setpoint This allows any condensation to evaporate and be swept out of the detector Advanced User Guide Detectors 10 Maximum Bead Voltage Display only Shows the current maximum bead voltage for the configured bead type 4 095 V for ceramic beads Automatically adjusting NPD bead voltage Advanced User Guide Agilent recommends using the Adjust offset feature to automatically determine the lowest bead voltage needed to give the desired response When the detector is turned on the temperature rises at a controlled rate e If Dry Bead is On temperature holds at 150 C for 5 minutes to drive off moisture then continues to the setpoint If Dry Bead is Off the temperature rises directly to the setpoint When the temperature reaches the setpoint the Bead Voltage gradually rises until it produces the desired output Adjust offset
147. witching a valve can cause baseline upsets Other factors can cause baseline upsets also The GC can compensate for this by pausing freezing the signal at a particular value using that signal value for a specified duration and then resuming normal signal output Consider a system that uses a switching valve When the valve switches an anomaly occurs in the baseline By freezing and resuming the signal the anomaly can be removed so that the peak identification and integration software operates more smoothly Advanced User Guide GC Output Signals 13 Baseline upset due to valve switch Pause signal here Data rates with Agilent data systems Advanced User Guide Resume signal here The GC can process data at various data rates each corresponding to a minimum peak width The table shows the effect of data rate selection Table 38 EZChrom ChemStation data processing Data rate Hz Minimum peak width minutes Relative Detector noise Column type 500 0 0001 200 0 001 100 0 002 50 0 004 20 0 01 10 0 02 5 FID 3 1 FID 2 2 FID NPD only 1 6 1 0 7 Narrow bore 0 05 mm Narrow bore 0 05 mm Capillary 201 13 GC Output Signals 202 Table 38 EZChrom ChemStation data processing continued Data rate Hz Minimum peak Relative Detector Column type width minutes noise 5 0 04 0 5 to 2 0 1 0 3 All types 1 0 2 0 22 0 5 0 4 0 16 0 2 1 0 0 10 0 1 2 0 0 07 Slow packed Y
148. ximum temperature Maximum allowable oven temperature setpoint Some accessories such as the valve box valves and columns have specific temperature limits When configuring Maximum temperature these limits should be considered so that the accessories are not damaged Oven setpoints are verified as they are entered a message is displayed when an entered setpoint is inconsistent with a previously defined maximum Equilibration time The time required for the oven temperature to equilibrate after temperature is modified Equilibration time begins when the actual oven temperature comes within 1 C of the oven temperature setting The Equilibration time setpoint can be 0 to 999 99 minutes 129 9 Columns and Oven About Oven Temperature Programming Initial temperature Initial temperature 130 Initial time 1 Final temperature 1 Rate 1 Initial time 1 Final temperature 1 You can program the oven temperature from an initial temperature to a final temperature using up to 5 ramps during a run A single ramp temperature program raises the initial oven temperature to a specified final temperature at a specified rate and holds at the final temperature for a specified period of time Final time 1 Rate 1 Rate 2 0 The multiple ramp temperature program is similar You can program the oven from an initial temperature to a final temperature but with various rates times and temperatures in between Multiple ramps can also
149. xt run the bead will ignite almost immediately The process can be automated with Run Table entries Turning off the detector If you turn Adjust offset Off at any time the bead voltage hydrogen and air flows all turn off Setting the initial bead voltage for new beads Before you turn on the bead for the first time manually set its voltage to a safe value so that the new bead is not destroyed 1 Make sure Adjust Offset is turned Off 2 After the temperature stabilizes at setpoint set the initial Bead Voltage depending on bead type Ceramic bead white or black 0 0 V to 2 0 V Setting NPD bead voltage manually optional Advanced User Guide Bead voltage shows the voltage used to heat the bead It can be a value derived from the Adjust offset value or can be entered as a setpoint Entering a setpoint causes the voltage to change at 13 mV second until it reaches the setpoint provided that e the detector is at the temperature setpoint e temperature is at least 150 C e gas flows are on Dry Bead time if On has elapsed Bead voltage is also useful for small adjustments between runs If you observe a baseline drift you can enter a small one time change to compensate for the drift If you are not using the recommended Adjust offset process note that large voltage jumps reduce bead life Use increments no greater than 0 05 V spaced 10 seconds apart until you reach the desired offset 169 10 Detecto

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