1 METHOD 30B – DETERMINATION OF TOTAL
Contents
1. 27 in section 16 of Method 5 in appendix A 3 to this part If a dry gas meter is being calibrated use at least five revolutions of the meter at each flow rate 10 2 2 2 Alternative Initial Calibration Procedures Alternatively you may perform the initial calibration of the gas flow meter using a reference gas flow meter RGFM The RGFM may be 1 a wet test meter calibrated according to section 10 3 1 of Method 5 in appendix A 3 to this part 2 a gas flow metering device calibrated at multiple flow rates using the procedures in section 16 of Method 5 in appendix A 3 to this part or 3 a NIST traceable calibration device capable of measuring volumetric flow to an accuracy of 1 percent To calibrate the gas flow meter using the RGFM proceed as follows While the Method 30B sampling system is sampling the actual stack gas or a compressed gas mixture that simulates the stack gas composition as applicable connect the RGFM to the discharge of the system Care should be taken to minimize the dead volume between the gas flow meter being tested and the RGFM Concurrently measure dry stack gas volume with the RGFM and the flow meter being calibrated for at least 10 minutes at each of three flow rates covering the typical range of operation of the sampling system For each set of concurrent measurements record the total sample volume in units of dry standard cubic meters dscm measured by the RGFM and the gas flow meter being tested 10 2 22. 3 Initial Calibration Factor Calculate an individual calibration factor Y at each tested flow rate from section 10 2 2 1 or 10 2 2 2 of this method as applicable by taking the ratio of the reference sample volume to the sample volume recorded by the gas flow meter Average the three Y values to determine Y the calibration factor for the flow meter Each of the three individual values of Y must be within 0 02 of Y Except 28 as otherwise provided in sections 10 2 2 4 and 10 2 2 5 of this method use the average Y value from the initial 3 point calibration to adjust subsequent gas volume measurements made with the gas flow meter 10 2 2 4 Pretest On Site Calibration Check Optional For a mass flow meter if the most recent 3 point calibration of the flow meter was performed using a compressed gas mixture you may want to conduct the following on site calibration check prior to testing to ensure that the flow meter will accurately measure the volume of the stack gas While sampling stack gas check the calibration of the flow meter at one intermediate flow rate setting representative of normal operation of the sampling system If the pretest calibration check shows that the value of Yj the calibration factor at the tested flow rate differs from the current value of Y by more than 5 percent perform a full 3 point recalibration of the meter using stack gas to determine a new value of Y and except as otherwise provided in section 10 2
3. Analysis of independent calibration standard Analysis of continuing calibration verification standard CCVS Test run total sample volume Establish minimum dilution if any needed to eliminate sorbent matrix interferences Average recovery between 90 and 110 for Hg and HgCl at each of the 2 spike concentration levels Each analyzer reading within 10 of true value and r gt 0 99 Within 10 of true value Within 10 of true value Within 20 of total volume sampled during field recovery test 25 Prior to analyzing any field samples repeat for each type of sorbent used Prior to analyzing field samples and prior to use of new sorbent media On the day of analysis before analyzing any samples Following daily calibration prior to analyzing field samples Following daily calibration after analyzing lt 10 field samples and at end of each set of analyses Each individual sample Field sample results not validated Field samples shall not be analyzed until the percent recovery criteria has been met Recalibrate until successful Recalibrate and repeat independent standard analysis until successful Recalibrate and repeat independent standard analysis reanalyze samples until successful if possible for destructive techniques samples invalidated Sample invalidated QA QC Test or Acceptance Criteria Frequency Consequences Speci
4. during that test program The conduct of this test requires an estimate or confirmation of the stack Hg concentrations at the time of testing 8 2 6 1 Calculation of Pre sampling Spiking Level Determine the sorbent trap spiking level for the field recovery test using estimates of the stack Hg concentration the target sample flow rate and the planned sample duration First determine the Hg mass 18 expected to be collected in section 1 of the sorbent trap The pre sampling spike must be within 50 to150 percent of this expected mass Example calculation For an expected stack Hg concentration of 5 ug m ng L a target sample rate of 0 40 liters min and a sample duration of 1 hour 0 40 L min 60 min 5ng L 120 ng A Hg spike of 60 to 180 ng 50 150 of 120 ng would be appropriate 8 2 6 2 Procedures Set up two identical sampling trains One of the sampling trains shall be designated the spiked train and the other the unspiked train Spike Hg onto the front section of the sorbent trap in the spiked train before sampling The mass of Hg spiked shall be 50 to 150 percent of the mass expected to be collected with the unspiked train Sample the stack gas with the two trains simultaneously using the same procedures as for the field samples see Section 8 3 The total sample volume must be within 20 percent of the target sample volume for the field sample test runs Analyze the sorbent traps from the two trains utilizing the same analyt
5. is required for all analytical techniques Based on the analytical approach you employ you should determine the most sensitive calibration range Based on a calibration point within that range you must consider all sample treatments e g dilutions to determine the mass of sample that needs 13 to be collected to ensure that all sample analyses fall within your calibration curve 8 2 2 1 Determination of Minimum Calibration Concentration or Mass Based on your instrument s sensitivity and linearity determine the calibration concentrations or masses that make up a representative low level calibration range Verify that you are able to meet the multipoint calibration performance criteria in section 11 0 of this method Select a calibration concentration or mass that is no less than 2 times the lowest concentration or mass in your calibration curve The lowest point in your calibration curve must be at least 5 and preferably10 times the Method Detection Limit MDL which is the minimum amount of the analyte that can be detected and reported The MDL must be determined at least once for the analytical system using an MDL study such as that found in section 17 0 of the proposed amendments to EPA Method 301 69 FR 76642 12 22 2004 Note to Section 8 2 2 1 While it might be desirable to base the minimum calibration concentration or mass on the lowest point in the calibration curve selecting a higher concentration or mass is necessary to ensur
6. per dry standard cubic meter ug dscm Analyte CAS No Analytical Range and Sensitivity Elemental Hg Hg 7439 97 6 Typically 0 1 ug dsem to gt 50 ug dsem Oxidized Hg Hg Same 1 2 Applicability When is this method required Method 30B is a reference method for relative accuracy test audits RATAs of vapor phase Hg CEMS and sorbent trap monitoring systems installed at coal fired boilers and is also appropriate for Hg emissions testing at such boilers It is intended for use only under relatively low particulate conditions i e sampling after all pollution control devices in cases where significant amounts of particle bound Hg may be present an isokinetic sampling method for Hg should be used Method 30B may also be specified by New Source Performance Standards NSPS National Emission Standards for Hazardous Air Pollutants NESHAP emissions trading programs State Implementation Plans SIPs and operating permits that require measurement of Hg concentrations in stationary source emissions either to determine compliance with an applicable emission standard or limit or to conduct RATAs of Hg CEMS and sorbent trap monitoring systems 1 3 Data Quality Objectives DQO How good must my collected data be Method 30B has been designed to provide data of high and known quality for Hg emissions testing and for RATA testing of Hg monitoring systems including CEMS and sorbent trap monitors In these and other ap
7. to directly calibrate analytical systems 3 3 Independent Calibration Standard is a NIST traceable standard obtained from a source or supplier independent of that for the calibration standards and is used to confirm the integrity of the calibration standards used 3 4 Method Detection Limit MDL is the lowest mass of Hg greater than zero that can be estimated and reported by your candidate analytical technique The MDL is statistically derived from replicate low level measurements near your analytical instrument s detection level 3 5 NIST means the National Institute of Standards and Technology located in Gaithersburg Maryland 3 6 Run means a series of gas samples taken successively from the stack or duct A test normally consists of a specific number of runs 3 7 Sorbent Trap means a cartridge or sleeve containing a sorbent media typically activated carbon treated with iodine or some other halogen with multiple sections separated by an inert material such as glass wool These sorbent traps are optimized for the quantitative capture of elemental and oxidized forms of Hg and can be analyzed by multiple techniques 3 8 Test refers to the series of runs required by the applicable regulation 3 9 Thermal Analysis means an analytical technique where the contents of the sorbent traps are analyzed using a thermal technique desorption or combustion to release the captured Hg in a detectable form for quantification 3 10 Wet Analysis means
8. 10 2 Gas Flow Meter Calibration 10 2 1 Preliminaries The manufacturer or equipment supplier of the gas flow meter should perform all necessary set up testing programming etc and should provide the end user with any necessary instructions to ensure that the meter will give an accurate readout of dry gas volume in standard cubic meters for this method 10 2 2 Initial Calibration Prior to its initial use a calibration of the gas flow meter shall be performed The initial calibration may be done by the manufacturer by the equipment supplier or by the end user If the flow meter is volumetric in nature e g a dry gas meter the manufacturer or end user may perform a direct volumetric calibration using any gas For a mass flow meter the manufacturer equipment supplier or end user may calibrate the meter using either 1 a bottled gas mixture containing 12 0 5 CO 7 0 5 Oz and balance Nz when this method is applied to coal fired boilers 2 a bottled gas mixture containing CO2 O2 and N2 in proportions representative of the expected stack gas composition or 3 the actual stack gas 10 2 2 1 Initial Calibration Procedures Determine an average calibration factor Y for the gas flow meter by calibrating it at three sample flow rate settings covering the range of sample flow rates at which the sampling system will be operated You may either follow the procedures in section 10 3 1 of Method 5 in appendix A 3 to this part or
9. 2 5 of this method apply the new Y value to the data recorded during the field test 10 2 2 5 Post Test Calibration Check Check the calibration of the gas flow meter following each field test at one intermediate flow rate setting either at or in close proximity to the average sample flow rate during the field test For dry gas meters ensure at least three revolutions of the meter during the calibration check For mass flow meters this check must be performed before leaving the test site while sampling stack gas If a one point calibration check shows that the value of Y at the tested flow rate differs by more than 5 percent from the current value of Y repeat the full 3 point calibration procedure to determine a new value of Y and apply the new Y value to the gas volume measurements made with the gas flow meter during the field test that was just 29 completed For mass flow meters perform the 3 point recalibration while sampling stack gas 10 3 Thermocouples and Other Temperature Sensors Use the procedures and criteria in Section 10 3 of Method 2 in Appendix A 1 to this part to calibrate in stack temperature sensors and thermocouples Dial thermometers shall be calibrated against mercury in glass thermometers Calibrations must be performed prior to initial use and before each field test thereafter At each calibration point the absolute temperature measured by the temperature sensor must agree to within 1 5 percent of the temperat
10. Calculation of Hg Concentration Calculate the Hg concentration measured with sorbent trap a using Equation 30B 3 Gia mim Eq 30B 3 For sorbent trap b replace Ca with C in Equation 30B 3 Report the average concentration i e 2 Ca Cp 12 5 Moisture Correction Use Equation 30B 4 if your measurements need to be corrected to a wet basis C C 1 B Eq 30B 4 35 12 6 Calculation of Paired Trap Agreement Calculate the relative deviation RD between the Hg concentrations measured with the paired sorbent traps using Equation 30B 5 C C IC Gl 00 Eq 30B 5 Cur 12 7 Calculation of Measured Spike Hg Concentration Field Recovery Test Calculate the measured spike concentration using Equation 30B 6 ee is ae Eq 30B 6 V v Then calculate the spiked Hg recovery R using Equation 30B 7 ERA Eq 30B 7 M spiked 13 0 Method Performance How do I validate my data Measurement data are validated using initial one time laboratory tests coupled with test program specific tests and procedures The analytical matrix interference test and the Hg and HgCl analytical bias test described in Section 8 2 are used to verify the appropriateness of the selected analytical approach es as well as define the valid working ranges for sample analysis The field recovery test serves to verify the performance of the combined sampling and analysis as applied for each test program Fie
11. Carefully separate the sections of each sorbent trap Combine for analysis all materials associated with each section any supporting substrate 31 that the sample gas passes through prior to entering a media section e g glass wool separators acid gas traps etc must be analyzed with that segment 11 3 Field Sample Analyses Analyze the sorbent trap samples following the same procedures that were used for conducting the Hg and HgCl analytical bias tests The individual sections of the sorbent trap and their respective components must be analyzed separately i e section 1 and its components then section 2 and its components All sorbent trap section 1 sample analyses must be within the calibrated range of the analytical system For wet analyses the sample can simply be diluted to fall within the calibrated range However for the destructive thermal analyses samples that are not within the calibrated range cannot be re analyzed As a result the sample cannot be validated and another sample must be collected It is strongly suggested that the analytical system be calibrated over multiple ranges so that thermally analyzed samples do fall within the calibrated range The total mass of Hg measured in each sorbent trap section 1 must also fall within the lower and upper mass limits established during the initial Hg and HgCl analytical bias test If a sample is analyzed and found to fall outside of these limits it is acceptable for an a
12. METHOD 30B DETERMINATION OF TOTAL VAPOR PHASE MERCURY EMISSIONS FROM COAL FIRED COMBUSTION SOURCES USING CARBON SORBENT TRAPS 1 0 Scope and Application What is Method 30B Method 30B is a procedure for measuring total vapor phase mercury Hg emissions from coal fired combustion sources using sorbent trap sampling and an extractive or thermal analytical technique This method is only intended for use only under relatively low particulate conditions e g sampling after all pollution control devices Quality assurance and quality control requirements are included to assure that you the tester collect data of known and acceptable quality for each testing program This method does not completely describe all equipment supplies and sampling and analytical procedures you will need but instead refers to other test methods for some of the details Therefore to obtain reliable results you should also have a thorough knowledge of these additional methods which are found in Appendices A 1 and A 3 to this part a Method 1 Sample and Velocity Traverses for Stationary Sources b Method 4 Determination of Moisture Content in Stack Gases c Method 5 Determination of Particulate Matter Emissions from Stationary Sources 1 1 Analytes What does this method determine This method is designed to measure the mass concentration of total vapor phase Hg in flue gas including elemental Hg Hg and oxidized forms of Hg Hg in micrograms
13. With this system an aliquot of known volume and concentration is added to a reaction vessel containing a reducing agent e g stannous chloride the Hg salt solution is reduced to Hg and purged onto the sorbent trap using an impinger sparging system When available information on example spiking systems will be posted at http www epa gov ttn emc 6 3 Sample Analysis Equipment Any analytical system capable of quantitatively recovering and quantifying total Hg from the sorbent media selected is acceptable provided that the analysis can meet the performance criteria described in this method Example recovery techniques include acid leaching digestion and thermal desorption direct combustion Example analytical techniques include but are not limited to ultraviolet atomic fluorescence UV AF ultraviolet atomic absorption UV AA with and without gold trapping and X ray fluorescence XRF analysis 6 3 Moisture Measurement System If correction of the measured Hg emissions for moisture is required see Section 8 3 3 7 either Method 4 in Appendix A 3 to this part or other moisture measurement methods approved by the Administrator will be needed to measure stack gas moisture content 7 0 Reagents and Standards 7 1 Reagents and Standards Only NIST certified or NIST traceable calibration standards standard reference materials and reagents shall be used for the tests and procedures required by this method 7 2 Sorbent Trap Media The so
14. an analytical technique where the contents of the sorbent tube are first leached or digested to quantitatively transfer the captured Hg to liquid solution for subsequent analysis 4 0 Interferences Interferences may result from the sorbent trap material used as well as from the measurement environment itself The iodine present on some sorbent traps may impart a negative measurement bias High levels of sulfur trioxide SO3 are also suspected to compromise the performance of sorbent trap Hg capture These and other potential interferences are assessed by performing the analytical matrix interference Hg and HgCl analytical bias and field recovery tests 5 0 Safety What safety measures should I consider when using this method This method may require you to work with hazardous materials and in hazardous conditions You are encouraged to establish safety procedures before using the method Among other precautions you should become familiar with the safety recommendations in the gas analyzer user s manual Occupational Safety and Health Administration OSHA regulations concerning use of compressed gas cylinders and noxious gases may apply 5 1 Site Hazards Prior to applying these procedures specifications in the field the potential hazards at the test site should be considered advance coordination with the site is critical to understand the conditions and applicable safety policies At a minimum portions of the sampling system will be h
15. bes and inserted directly into the flue gas stream 6 1 2 Sampling Probe Assembly Each probe assembly shall have a leak free attachment to the sorbent trap s Each sorbent trap must be mounted at the entrance of or within the probe such that the gas sampled enters the trap directly Each probe sorbent trap assembly must be heated to a temperature sufficient to prevent liquid condensation in the sorbent trap s Auxiliary heating is required only where the stack temperature is too low to prevent condensation Use a calibrated thermocouple to monitor the stack temperature A single probe capable of operating the paired sorbent traps may be used Alternatively individual probe sorbent trap assemblies may be used provided that the individual sorbent traps are co located to ensure representative Hg monitoring 6 1 3 Moisture Removal Device A moisture removal device or system shall be used to remove water vapor from the gas stream prior to entering dry gas flow metering devices 6 1 4 Vacuum Pump Use a leak tight vacuum pump capable of operating within the system s flow range 6 1 5 Gas Flow Meter A gas flow meter such as a dry gas meter thermal mass flow meter or other suitable measurement device shall be used to determine the total sample volume on a dry basis in units of standard cubic meters The meter must be sufficiently accurate to measure the total sample volume to within 2 percent and must be calibrated at selected flow rates acr
16. calibrated if necessary The field samples analyzed must fall within a calibrated quantitative range and meet the performance criteria specified below For samples suitable for aliquotting a series of dilutions may be needed to ensure that the samples fall within a calibrated range However for sorbent media samples consumed during analysis e g when using thermal desorption techniques extra care must be taken to ensure that the analytical system is appropriately calibrated prior to sample analysis The calibration curve range s should be determined such that the levels of Hg mass expected to be collected and measured will fall within the calibrated range The calibration curve may be generated by directly introducing standard solutions into the analyzer or by spiking the standards onto the sorbent media and then introducing into the analyzer after preparing the sorbent standard according to the particular analytical technique For each calibration curve the value of the square of the linear correlation coefficient i e r must be gt 0 99 and the analyzer response must be within 10 percent of the reference value at each upscale calibration point Calibrations must be performed on the day of the analysis before analyzing any of the samples Following calibration an independent standard shall be analyzed The measured value of the independently prepared standard must be within 10 percent of the expected value 11 2 Sample Preparation
17. calibration check Single point Temperature sensor calibration Barometer calibration Pre test leak check Post test leak check Calibration factor Y must be within 5 of the Y value from the most recent 3 point calibration Absolute temperature measured by sensor within 1 5 of a reference sensor Absolute pressure measured by instrument within 10 mm Hg of reading with a mercury barometer lt 4 of target sampling rate lt 4 of average sampling rate 24 post test check is not within 5 of Y After each field test For mass flow meters must be done on site using stack gas Prior to initial use and before each test thereafter Prior to initial use and before each test thereafter Prior to sampling After sampling acceptance criteria are met Recalibrate gas flow meter at 3 points to determine a new value of Y For mass flow meters must be done on site using stack gas Apply the new Y value to the field test data Recalibrate sensor may not be used until specification is met Recalibrate instrument may not be used until specification is met Sampling shall not commence until the leak check is passed Sample invalidated QA QC Test or Acceptance Criteria Frequency Consequences Specification if Not Met Analytical matrix interference test wet chemical analysis only Analytical bias test Multipoint analyzer calibration
18. dditional Hg and HgCl analytical bias test to be performed that now includes this level However some samples e g the mass collected in trap section 2 or the mass collected in trap section 1 when the stack gas concentration is lt 0 5 ug m3 may have Hg levels so low that it may not be possible to quantify them in the analytical system s calibrated range Because a reliable estimate of these low level Hg measurements is necessary to fully validate the emissions data the MDL see section 8 2 2 1 of this method is used to establish the minimum amount that can be detected and reported If the measured mass or concentration is below the lowest 32 point in the calibration curve and above the MDL the analyst must do the following estimate the mass or concentration of the sample based on the analytical instrument response relative to an additional calibration standard at a concentration or mass between the MDL and the lowest point in the calibration curve This is accomplished by establishing a response factor e g area counts per Hg mass or concentration and estimating the amount of Hg present in the sample based on the analytical response and this response factor Example The analysis of a particular sample results in a measured mass above the MDL but below the lowest point in the calibration curve which is 10 ng An MDL of 1 3 ng Hg has been established by the MDL study A calibration standard containing 5 ng of Hg is analyzed and give
19. e that all analyses of the field samples will fall within the calibration curve Therefore it is strongly recommended that you select a minimum calibration concentration or mass that is sufficiently above the lowest point of the calibration curve see examples in sections 8 2 2 2 1 and 8 2 2 2 2 below 8 2 2 2 Determination of Minimum Sample Mass Based on your minimum calibration concentration or mass and other sample treatments including but not limited to final digestate volume and minimum sample dilution determine the minimum sample mass Consideration should also be given to the Hg levels expected to be measured in Section 2 of the sorbent traps and to the breakthrough criteria presented in Table 9 1 14 8 2 2 2 1 Example Determination of Minimum Sample Mass for Thermal Desorption Analysis A thermal analysis system has been calibrated at five Hg mass levels 10 ng 20 ng 50 ng 100 ng 200 ng and shown to meet the calibration performance criteria in this method Based on 2 times the lowest point in the calibration curve 20 ng is selected as the minimum calibration mass Because the entire sample is analyzed and there are no dilutions involved the minimum sample mass is also 20 ng Note In this example if the typical background blank Hg levels in section 2 were relatively high e g 3 to 5 ng a sample mass of 20 ng might not have been sufficient to ensure that the breakthrough criteria in Table 9 1 would be met thereby necessitat
20. ements of the digestate to a fixed volume of the calibration standard and bringing each solution to a final fixed volume with mercury free deionized water diH20 To 2 0 ml of the calibration standard add 18 0 10 0 4 0 2 0 1 0 0 2 and 0 0 ml of the digestate Bring the final volume of each solution to a total volume of 20 ml by adding 0 0 8 0 14 0 16 0 17 0 17 8 and 18 0 ml of diH2O This will yield solutions with dilution ratios of 9 10 1 2 1 5 1 10 1 20 1 100 and 0 10 respectively Determine the Hg concentration of each solution The dilution ratio of any solution having a concentration that is within 5 percent of the concentration of the solution containing 0 0 ml of digestate is an acceptable dilution ratio for analyzing field samples If more than one solution meets this criterion the one with the lowest dilution ratio is the minimum dilution required for analysis of field samples If the 9 10 dilution meets this criterion then no sample dilution is required 8 2 2 Determination of Minimum Sample Mass The minimum mass of Hg that must be collected per sample must be determined This information is necessary in order to effectively perform the Hg and HgCl Analytical Bias Test to estimate target sample volumes sample times for test runs and to ensure the quality of the measurements The determination of minimum sample mass is a direct function of analytical technique measurement sensitivity dilutions etc This determination
21. fication if Not Met Sorbent trap section 2 breakthrough Paired sorbent trap agreement Sample analysis Sample analysis Field recovery test lt 10 of section 1 Hg mass for Hg concentrations gt 1 ug dscm lt 20 of section 1 Hg mass for Hg concentrations lt 1 pg dscm lt 10 Relative Deviation RD mass for Hg concentrations gt 1 ug dscm lt 20 RD or lt 0 2 ug dscm absolute difference for Hg concentrations lt 1 pg dscm Within valid calibration range within calibration curve Within bounds of Hg and HgCl Analytical Bias Test Average recovery between 85 and 115 for Hg Every sample All Section 1 samples where stack Hg concentration is gt 0 5 ug dscm All Section 1 samples where stack Hg concentration is gt 0 5 ug dscm Once per field test And data from the pair of sorbent traps are also invalidated 26 Sample invalidated Run invalidated Reanalyze at more concentrated level if possible samples invalidated if not within calibrated range Expand bounds of Hg and HgCl Analytical Bias Test if not successful samples invalidated Field sample runs not validated without successful field recovery test 10 0 Calibration and Standardization 10 1 Only NIST certified and NIST traceable calibration standards 1 e calibration gases solutions etc shall be used for the spiking and analytical procedures in this method
22. for sorbent traps spiked with Hg and HgCl The analytical bias test is performed at a minimum of two distinct sorbent trap Hg loadings that will 1 represent the lower and upper bound of sample Hg loadings for application of the analytical technique to the field samples and 2 be used for data validation 8 2 3 1 Hg and HgCl Analytical Bias Test Procedures Determine the lower and upper bound mass loadings The minimum sample mass established in Section 8 2 2 2 can be used for the lower bound Hg mass loading although lower Hg loading levels are acceptable The upper bound Hg loading level should be an estimate of the greatest mass loading that may result as a function of stack concentration and volume sampled As previously noted this test defines the bounds that actual field samples must be within in order to be valid 8 2 3 1 1 Hg Analytical Bias Test Analyze the front section of three sorbent traps containing Hg at the lower bound mass loading level and the front section of three sorbent traps containing Hg at the upper bound mass loading level In other words analyze each mass loading level in triplicate You may refer to Section 6 2 for spiking guidance Prepare and analyze each spiked trap using the same techniques that will be used to prepare and analyze the field samples The average recovery for the three traps at 16 each mass loading level must be between 90 and 110 percent If multiple types of sorbent media are t
23. gnized that additional equipment and supplies may be needed Collection of paired samples is required 6 1 Sorbent Trap Sampling System A typical sorbent trap sampling system is shown in Figure 30B 1 in Section 17 0 The sorbent trap sampling system shall include the following components 6 1 1 Sorbent Traps The sorbent media used to collect Hg must be configured in a trap with at least two distinct segments or sections connected in series that are amenable to separate analyses Section is designated for primary capture of gaseous Hg Section 2 is designated as a backup section for determination of vapor phase Hg breakthrough Each sorbent trap must be inscribed or otherwise permanently marked with a unique identification number for tracking purposes The sorbent media may be any collection material e g carbon chemically treated filter etc capable of quantitatively capturing and recovering for subsequent analysis all gaseous forms of Hg in the emissions from the intended application Selection of the sorbent media shall be based on the material s ability to achieve the performance criteria contained in this method as well as the sorbent s vapor phase Hg capture efficiency for the emissions matrix and the expected sampling duration at the test site The sorbent media must be obtained from a source that can demonstrate their quality assurance and quality control see Section 7 2 The paired sorbent traps are supported on a probe or pro
24. he run start time 8 3 3 3 Record the initial gas flow meter reading stack temperature meter temperatures if needed and any other appropriate information before beginning sampling Begin sampling and target a sampling flow rate similar to that for the field recovery test Then at regular intervals lt 5 minutes during the sampling period record the date and time the sample flow rate the gas meter reading the stack temperature the flow meter temperatures if using a dry gas meter temperatures of heated equipment such as the vacuum lines and the probes if heated and the sampling system vacuum readings Adjust the sampling flow rate as necessary to maintain the initial sample flow rate Ensure that the total volume sampled for each run is within 20 percent of the total volume sampled for the field recovery test 8 3 3 4 Data Recording Obtain and record any essential operating data for the facility during the test period e g the barometric pressure must be obtained for correcting sample volume to standard conditions when using a dry gas meter At the end of the data collection period record the final gas flow meter reading and the final values of all other essential parameters 8 3 3 5 Post Test Leak Check When sampling is completed turn off the sample 21 pump remove the probe s with sorbent traps from the port and carefully seal the end of each sorbent trap Perform another leak check of each sampling train with the sorbe
25. ical procedures and instrumentation as for the field samples see Section 11 0 Determine the fraction of spiked Hg recovered R using the equations in Section 12 7 Repeat this procedure for a total of three runs Report the individual R values in the test report the average of the three R values must be between 85 and 115 percent Note to section 8 2 6 2 It is acceptable to perform the field recovery test concurrent with actual test runs e g through the use of a quad probe It is also acceptable to use the field recovery test runs as test runs for emissions testing or for the RATA of a Hg monitoring system under part 75 of this chapter and Performance Specification 12A in appendix B to this part if certain conditions are met To determine 19 whether a particular field recovery test run may be used as a RATA run subtract the mass of the Hg spike from the total Hg mass collected in sections 1 and 2 of the spiked trap The difference represents the mass of Hg in the stack gas sample Divide this mass by the sample volume to obtain the Hg concentration in the effluent gas stream as measured with the spiked trap Compare this concentration to the corresponding Hg concentration measured with the unspiked trap If the paired trains meet the relative deviation and other applicable data validation criteria in Table 9 1 then the average of the two Hg concentrations may be used as an emissions test run value or as the reference method value fo
26. ing the use of a higher point on the calibration curve e g 50 ng as the minimum calibration and sample mass 8 2 2 2 2 Example Determination of Minimum Sample Mass for Acid Leachate Digestate Analysis A cold vapor analysis system has been calibrated at four Hg concentration levels 2 ng L 5 ng 10 ng L 20 ng L and shown to meet the calibration performance criteria in this method Based on 2 times the lowest point in the calibration curve 4 ng L was selected as the minimum calibration concentration The final sample volume of a digestate is nominally 50 ml 0 05 L and the minimum dilution necessary was determined to be 1 100 by the Analytical Matrix Interference Test of Section 8 2 1 The following calculation would be used to determine the minimum sample mass Minimum sample mass 4 ng L X 0 05 L X 100 20 ng Note In this example if the typical background blank Hg levels in section 2 were relatively high e g 3 to 5 ng a sample mass of 20 ng might not have been sufficient to 15 ensure that the breakthrough criterion in Table 9 1 would be met thereby necessitating the use of a higher point on the calibration curve e g 10 ng L as the minimum calibration concentration 8 2 3 Hg and HgCl Analytical Bias Test Before analyzing any field samples the laboratory must demonstrate the ability to recover and accurately quantify Hg and HgCl from the chosen sorbent media by performing the following analytical bias test
27. ld test samples are validated by meeting the above requirements as 36 well as meeting specific sampling requirements i e leak checks paired train agreement total sample volume agreement with field recovery test samples and analytical requirements i e valid calibration curve continuing calibration performance sample results within calibration curve and bounds of Hg and HgCl analytical bias test Complete data validation requirements are summarized in Table 9 1 14 0 Pollution Prevention Reserved 15 0 Waste Management Reserved 16 0 References 1 EPA Traceability Protocol for Qualification and Certification of Elemental Mercury Gas Generators expected publication date December 2008 see www epa gov ttn emc 2 EPA Traceability Protocol for Qualification and Certification of Oxidized Mercury Gas Generators expected publication date December 2008 see www epa gov ttn emc 3 EPA Traceability Protocol for Assay and Certification of Gaseous Calibration Standards expected revision publication date December 2008 see www epa gov ttn emc 17 0 Figures and Tables 37 Duct VVall Temperature Sensor Water Desiccant Knockout Port Probe Flanges Isolation Vacuum Valve Flow Control Gauge Valve x Gas Inlet gt Mercury Sample Line Trap Isolation Valve Probe Discharge C Thermocouple for Dry Gas Meters Sampling Console Figure 30B 1 Typical Sorbent Trap Sam
28. me Target Sample Volume 50 ng 2 ng L 25 L Note For the purposes of relative accuracy testing of Hg monitoring systems under part 17 75 of this chapter and Performance Specification 12A in appendix B to this part when the stack gas Hg concentration is expected to be very low lt 0 5 pg dscm you may estimate the Hg concentration at 0 5 g dscm 8 2 5 Determination of Sample Run Time Sample run time will be a function of minimum sample mass see Section 8 2 2 target sample volume and nominal equipment sample flow rate The minimum sample run time for conducting relative accuracy test audits of Hg monitoring systems is 30 minutes and for emissions testing to characterize an emission source is hour The target sample run time can be calculated using the following example Example If the target sample volume has been determined to be 25 L then the following formula would be used to determine the sampling time necessary to acquire 25 L of gas when sampling at a rate of 0 4 L min Sampling time min 25 L 0 4 L min 63 minutes 8 2 6 Field Recovery Test The field recovery test provides a test program specific verification of the performance of the combined sampling and analytical approach Three sets of paired samples one of each pair which is spiked with a known level of Hg are collected and analyzed and the average recovery of the spiked samples is used to verify performance of the measurement system under field conditions
29. mpling and analysis The test shall be performed using a mass of sorbent material comparable to the sorbent mass typically used in the first section of the trap for sampling Similar sorbent materials from different sources of supply are considered to be different materials and must be tested individually You must conduct the analytical matrix interference test for each sorbent material prior to the analysis of field samples 8 2 1 1 Analytical Matrix Interference Test Procedures Digest and prepare for analysis a representative mass of sorbent material unsampled according to your intended laboratory techniques for field samples Analyze the digestate according to your intended analytical conditions at the least diluted level you intend to use for sample analysis e g undiluted 1 in 10 dilution etc Determine the Hg concentration of the 11 undiluted digestate solution Prepare a series of solutions with a fixed final volume containing graduated aliquots of the sample digestate and a fixed aliquot of a calibration standard with the balance being Hg free reagent or H20 to establish solutions of varied digestate dilution ratio e g 1 2 1 5 1 10 1 100 etc see example in Section 8 2 1 3 below One of these solutions should contain only the aliquot of the calibration standard in Hg free reagent or H20 This will result in a series of solutions where the amount of Hg is held relatively constant and only the volume of digestate diluted i
30. nt trap in place at the maximum vacuum reached during the sampling period Record the leakage rates and vacuums The leakage rate for each train must not exceed 4 percent of the average sampling rate for the data collection period Following each leak check carefully release the vacuum in the sample train 8 3 3 6 Sample Recovery Recover each sampled sorbent trap by removing it from the probe and sealing both ends Wipe any deposited material from the outside of the sorbent trap Place the sorbent trap into an appropriate sample storage container and store preserve in appropriate manner see Section 8 3 3 8 8 3 3 7 Stack Gas Moisture Determination If the moisture basis of the measurements made with this method dry is different from the moisture basis of either 1 the applicable emission limit or 2 a Hg CEMS being evaluated for relative accuracy you must determine the moisture content of the flue gas and correct for moisture using Method 4 in appendix A 3 to this part If correction of the measured Hg concentrations for moisture is required at least one Method 4 moisture determination shall be made during each test run 8 3 3 8 Sample Handling Preservation Storage and Transport While the performance criteria of this approach provide for verification of appropriate sample handling it is still important that the user consider determine and plan for suitable sample preservation storage transport and holding times for these measuremen
31. o be analyzed a separate analytical bias test is required for each sorbent material 8 2 3 1 2 HgCl Analytical Bias Test Analyze the front section of three sorbent traps containing HgCl at the lower bound mass loading level and the front section of three traps containing Hg Cl at the upper bound mass loading level HgCl can be spiked as a gas or as a liquid solution containing HgCly However the liquid volume spiked must be lt 100 uL Prepare and analyze each spiked trap using the techniques that will be used to prepare and analyze the field samples The average recovery for three traps at each spike concentration must be between 90 and 110 percent Again if multiple types of sorbent media are to be analyzed a separate analytical bias test is required for each sorbent material 8 2 4 Determination of Target Sample Volume The target sample volume is an estimate of the sample volume needed to ensure that valid emissions data are collected i e that sample mass Hg loadings fall within the analytical calibration curve and are within the upper and lower bounds set by the analytical bias tests The target sample volume and minimum sample mass can also be determined by performing a diagnostic test run prior to initiation of formal testing Example If the minimum sample mass is 50 ng and the concentration of mercury in the stack gas is estimated to be 2 g m ng L then the following calculation would be used to determine the target sample volu
32. oss the range of sample flow rates at which the sampling train will be operated The gas flow meter shall be equipped with any necessary auxiliary measurement devices e g temperature sensors pressure measurement devices needed to correct the sample volume to standard conditions 6 1 6 Sample Flow Rate Meter and Controller Use a flow rate indicator and controller for maintaining necessary sampling flow rates 6 1 7 Temperature Sensor Same as Section 6 1 1 7 of Method 5 in Appendix A 3 to this part 6 1 8 Barometer Same as Section 6 1 2 of Method 5 in Appendix A 3 to this part 6 1 9 Data Logger optional Device for recording associated and necessary ancillary information e g temperatures pressures flow time etc 6 2 Gaseous Hg Sorbent Trap Spiking System A known mass of gaseous Hg must be either present on or spiked onto the first section of sorbent traps in order to perform the Hg and HgCl analytical bias test and the field recovery study Any approach capable of quantitatively delivering known masses of Hg onto sorbent traps is acceptable Several spiking technologies or devices are available to meet this objective Their practicality is a function of Hg mass spike levels For low levels NIST certified or NIST traceable gas generators or tanks may be suitable An alternative system capable of delivering almost any mass required makes use of NIST certified or NIST traceable Hg salt solutions e g HgClo Hg NO3 2
33. ot requiring appropriate gloves long sleeves and caution in handling this equipment 5 2 Laboratory Safety Policies should be in place to minimize risk of chemical exposure and to properly handle waste disposal in the laboratory Personnel shall wear appropriate laboratory attire according to a Chemical Hygiene Plan established by the laboratory 5 3 Reagent Toxicity Carcinogenicity The toxicity and carcinogenicity of any reagents used must be considered Depending upon the sampling and analytical technologies selected this measurement may involve hazardous materials operations and equipment and this method does not address all of the safety problems associated with implementing this approach It is the responsibility of the user to establish appropriate safety and health practices and determine the applicable regulatory limitations prior to performance Any chemical should be regarded as a potential health hazard and exposure to these compounds should be minimized Chemists should refer to the Material Safety Data Sheet MSDS for each chemical used 5 4 Waste Disposal Any wastes generated by this procedure must be disposed of according to a hazardous materials management plan that details and tracks various waste streams and disposal procedures 6 0 Equipment and Supplies The following list is presented as an example of key equipment and supplies likely required to measure vapor phase Hg using a sorbent trap sampling system It is reco
34. p a ug dscm Concentration of Hg for the sample collection period for sorbent trap b ug dscm Hg concentration dry basis ug dscm Concentration of spiked compound measured ug m Hg concentration wet basis g m Mass of Hg measured on sorbent trap section 1 ug Mass of Hg measured on sorbent trap section 2 ug Mass of spiked Hg recovered in Analytical Bias or Field Recovery Test ug Total mass of Hg measured on spiked trap in Field Recovery Test ug Mass of Hg spiked in Analytical Bias or Field Recovery Test ug Total mass of Hg measured on unspiked trap in Field Recovery Test ug Percentage of spiked mass recovered Relative deviation between the Hg concentrations from traps a and bh Volume of gas sampled spiked trap in Field Recovery Test dscm 34 Vi Total volume of dry gas metered during the collection period dscm for the purposes of this method standard temperature and pressure are defined as 20 C and 760 mm Hg respectively Vu Volume of gas sampled unspiked trap in Field Recovery Test dscm 12 2 Calculation of Spike Recovery Analytical Bias Test Calculate the percent recovery of Hg and HgCh using Equation 30B 1 R Drecovered 100 Eq 30B 1 M piked 12 3 Calculation of Breakthrough Use Equation 30B 2 to calculate the percent breakthrough to the second section of the sorbent trap B x100 Eq 30B 2 m 12 4
35. plications the principal objective is to ensure the accuracy of the data at the actual emissions levels and in the actual emissions matrix encountered To meet this objective NIST traceable calibration standards must be used and method performance tests are required 2 0 Summary of Method Known volumes of flue gas are extracted from a stack or duct through paired in stack sorbent media traps at an appropriate flow rate Collection of mercury on the sorbent media in the stack mitigates potential loss of mercury during transport through a probe sample line For each test run paired train sampling is required to determine measurement precision and verify acceptability of the measured emissions data A field recovery test which assesses recovery of an elemental Hg spike to determine measurement bias is also used to verify data acceptability The sorbent traps are recovered from the sampling system prepared for analysis as needed and analyzed by any suitable determinative technique that can meet the performance criteria 3 0 Definitions 3 1 Analytical System is the combined equipment and apparatus used to perform sample analyses This includes any associated sample preparation apparatus e g digestion equipment spiking systems reduction devices etc as well as analytical instrumentation such as UV AA and UV AF cold vapor analyzers 3 2 Calibration Standards are the Hg containing solutions prepared from NIST traceable standards and are used
36. pling System 38 39
37. r a RATA run 8 3 Sampling This section describes the procedures and criteria for collecting the field samples for analysis As noted in Section 8 2 6 the field recovery test samples are also collected using these procedures 8 3 1 Pre test leak check Perform a leak check of the sampling system with the sorbent traps in place For each of the paired sampling trains draw a vacuum in the train and adjust the vacuum to 15 Hg and using the gas flow meter determine leak rate The leak rate for an individual train must not exceed 4 percent of the target sampling rate Once the leak check passes this criterion carefully release the vacuum in the sample train then seal the sorbent trap inlet until the probe is ready for insertion into the stack or duct 8 3 2 Determination of Flue Gas Characteristics Determine or measure the flue gas measurement environment characteristics gas temperature static pressure gas velocity stack moisture etc in order to determine ancillary requirements such as probe heating requirements if any initial sampling rate moisture management etc 20 8 3 3 Sample Collection 8 3 3 1 Remove the plug from the end of each sorbent trap and store each plug in a clean sorbent trap storage container Remove the stack or duct port cap and insert the probe s Secure the probe s and ensure that no leakage occurs between the duct and environment 8 3 3 2 Record initial data including the sorbent trap ID date and t
38. rbent trap media shall be prepared such that the material used for testing is of known and acceptable quality Sorbent supplier quality assurance quality control measures to ensure appropriate and consistent performance such as sorptive capacity uniformity of preparation treatments and background levels shall be considered 8 0 Sample Collection and Handling This section presents the sample collection and handling procedures along with the pretest and on site performance tests required by this method Since you may choose different options to comply with certain performance criteria each test report must identify the specific options selected and document the results with respect to the performance criteria of this method 8 1 Sample Point Selection What sampling site and sampling points do I select Same as Section 8 1 of Method 30A of this appendix 8 2 Measurement System Performance Tests What performance criteria must my measurement system meet The following laboratory and field procedures and associated criteria of this section are designed to ensure 1 selection of a sorbent and analytical technique combination capable of quantitative collection and analysis of gaseous Hg 2 collection of an adequate amount of Hg on each sorbent trap during field tests and 3 adequate performance of the method for each test program The primary objectives of these performance tests are to characterize and verify the performance of your intended anal
39. s an analytical response of 6 170 area counts which equates to a response factor of 1 234 area counts ng Hg The analytical response for the sample is 4 840 area counts Dividing the analytical response for the sample 4 840 area counts by the response factor gives 3 9 ng Hg which is the estimated mass of Hg in the sample 11 4 Analysis of Continuing Calibration Verification Standard CCVS After no more than 10 samples and at the end of each set of analyses a continuing calibration verification standard must be analyzed The measured value of the continuing calibration standard must be within 10 percent of the expected value 11 5 Blanks The analysis of blanks is optional The analysis of blanks is useful to verify the absence of or an acceptable level of Hg contamination Blank levels should be considered when quantifying low Hg levels and their potential contribution to meeting the sorbent trap section 2 breakthrough requirements however correcting sorbent trap results for blank levels is prohibited 33 12 0 Calculations and Data Analysis You must follow the procedures for calculation and data analysis listed in this section 12 1 Nomenclature The terms used in the equations are defined as follows B Mrecovered Ms Mspiked Mu Ww Vs II II Breakthrough Moisture content of sample gas as measured by Method 4 percent 100 Concentration of Hg for the sample collection period for sorbent tra
40. s varied Analyze each of these solutions following intended sample analytical procedures and conditions determining the concentration for each solution 8 2 1 2 Analytical Matrix Interference Test Acceptance Criteria Compare the measured concentration of each solution containing digestate to the measured concentration of the digestate free solution The lowest dilution ratio of any solution having a Hg concentration within 5 percent of the digestate free solution is the minimum dilution ratio required for analysis of all samples If you desire to measure the digestate without dilution the 5 percent criterion must be met at a dilution ratio of at least 9 10 i e gt 90 digestate 8 2 1 3 Example Analytical Matrix Interference Test An example analytical matrix interference test is presented below Additional information on the conduct of the analytical matrix interference test will be posted at http www epa gov ttn emc Determine the most sensitive working range for the analyzer to be used This will be a narrow range of concentrations Digest and prepare for analysis a representative mass of sorbent material unsampled according to your intended laboratory techniques for sample preparation and analysis Prepare a calibration curve for the most sensitive 12 analytical region e g 0 0 0 5 1 0 3 0 5 0 10 ppb Using the highest calibration standard e g 10 0 ppb prepare a series of solutions by adding successively smaller incr
41. ts Therefore procedures in ASTM WK223 Guide for Packaging and Shipping Environmental Samples for Laboratory Analysis shall be followed for all samples 22 where appropriate To avoid Hg contamination of the samples special attention should be paid to cleanliness during transport field handling sampling recovery and laboratory analysis as well as during preparation of the sorbent cartridges Collection and analysis of blank samples e g reagent sorbent field etc is useful in verifying the absence or source of contaminant Hg 8 3 3 9 Sample Custody Proper procedures and documentation for sample chain of custody are critical to ensuring data integrity The chain of custody procedures in ASTM D4840 99 Standard Guide for Sampling Chain of Custody Procedures shall be followed for all samples including field samples and blanks 9 0 Quality Assurance and Quality Control Table 9 1 summarizes the QA QC performance criteria that are used to validate the Hg emissions data from Method 30B sorbent trap measurement systems 23 Table 9 1 Quality Assurance Quality Control Criteria for Method 30B QA QC Test or Acceptance Criteria Frequency Consequences Specification if Not Met Gas flow meter Calibration factor Y at Prior to initial Recalibrate at 3 calibration each flow rate must be use and when points until the At 3 settings or within 2 of the points average value Y Gas flow meter post test
42. ure measured with the reference sensor otherwise the sensor may not continue to be used 10 4 Barometer Calibrate against a mercury barometer as per Section 10 6 of Method 5 in appendix A 3 to this part Calibration must be performed prior to initial use and before each test program and the absolute pressure measured by the barometer must agree to within 10 mm Hg of the pressure measured by the mercury barometer otherwise the barometer may not continue to be used 10 5 Other Sensors and Gauges Calibrate all other sensors and gauges according to the procedures specified by the instrument manufacturer s 10 6 Analytical System Calibration See Section 11 1 of this method 11 0 Analytical Procedures The analysis of Hg in the field and quality control samples may be conducted using any instrument or technology capable of quantifying total Hg from the sorbent media and meeting the performance criteria in this method Because multiple analytical approaches equipment and techniques are appropriate for the analysis of sorbent traps it is not possible to provide detailed technique specific analytical procedures As they 30 become available detailed procedures for a variety of candidate analytical approaches will be posted at http www epa gov ttn emc 11 1 Analytical System Calibration Perform a multipoint calibration of the analyzer at three or more upscale points over the desired quantitative range multiple calibration ranges shall be
43. ytical system and associated sampling and analytical procedures and to define the minimum amount of Hg as the sample collection target that can be quantified reliably a Analytical Matrix Interference Test b Determination of Minimum Sample Mass c Hg and HgCl Analytical Bias Test d Determination of Nominal Sample Volume e Field Recovery Test 10 8 2 1 Analytical Matrix Interference Test and Minimum Sample Dilution a The analytical matrix interference test is a laboratory procedure It is required only if you elect to use a liquid digestion analytical approach and needs to be performed only once for each sorbent material used The purpose of the test is to verify the presence or absence of known and potential analytical matrix interferences including the potential negative bias associated with iodine common to many sorbent trap materials The analytical matrix interference test determines the minimum dilution if any necessary to mitigate matrix effects on the sample digestate solutions b The result of the analytical matrix interference test i e the minimum sample dilution required if any for all sample analyses is used to establish the minimum sample mass needed for the Hg and HgCl analytical bias test and to determine the nominal sample volume for a test run The analytical matrix interference test is sorbent material specific and shall be performed for each sorbent material you intend to use for field sa
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