Chlorine Dioxide - Advance Laboratorios
Contents
1. Chlorine Dioxide DOC316 53 01021 DPD Method Method 10126 0 04 to 5 00 mg L Powder Pillows and AccuVac Ampuls Scope and Application For water and wastewater USEPA accepted for reporting for drinking water analysis 2 1 Adapted from Standard Methods for the Examination of Water and Wastewater 2 Procedure is equivalent to Standard Methods 18 ed 4500 CIO D Test preparation How to use instrument specific information The nstrument specific information table displays requirements that may vary between instruments To use this table select an instrument then read across to find the corresponding information required to perform this test Table 1 Instrument specific information Powder pillows AccuVac Ampuls Instrument Sample cell Cell orientation Sample cell Adapter DR 5000 2495402 Fill line faces user 2427606 DR 3900 2495402 Fill line faces user 2427606 LZV846 A DR 3800 DR 2800 DR 2700 2495402 Fill line faces right 2122800 LZV584 C Before starting the test Analyze samples immediately because chlorine dioxide is unstable and volatile See Sample collection preservation and storage For more accurate results determine a reagent blank value for each new lot of reagent Follow the procedure using deionized water instead of the sample Subtract the reagent blank value from the final results or perform a reagent blank adjust After adding the DPD Free Chlorine Powder Pillow to the sample a pink co2. Sodium Hydroxide 1 N 100 mL 104532 Standard Methods Book most current edition each 22 0800 Stopper for 18 mm tube 25 pkg 173125 Sulfuric Acid 1 N 100 mL each 127032 Chlorine Dioxide Page 7 of 8 FOR TECHNICAL ASSISTANCE PRICE INFORMATION AND ORDERING Inthe U S A Call toll free 800 227 4224 Outside the U S A Contact the HACH office or distributor serving you On the Worldwide Web www hach com E mail techhelp hach com Hach Company 2007 2010 All rights reserved Printed in the U S A HACH COMPANY WORLD HEADQUARTERS Telephone 970 669 3050 FAX 970 669 2932 Edition 6
3. alysis immediately Accuracy check Standard Solution Method Preparing chlorine dioxide standards is difficult and dangerous In addition these standards are both explosive and volatile Only a trained chemist should prepare the standards using appropriate safety equipment and precautions The manufacturer does not recommend preparation of chlorine dioxide standards If independent standard preparation is required please see the instructions in Standard Methods for the Examination of Water and Wastewater Part 4500 CIlO Chlorine Dioxide under the headings Stock chlorine dioxide solution and Standard chlorine dioxide solution Prepare a chlorine dioxide standard Chlorine Dioxide Page 5 of 8 Chlorine Dioxide Method performance Precision Sensitivity Program Standard 95 Confidence Limits of Concentration change Distribution per 0 010 Abs change DR 5000 3 00 mg L CIO 2 89 3 11 mg L CIO 0 04 mg L CIO DR 5000 3 00 mg L CIO 2 91 3 09 mg L CIO 0 04 mg L CIO Summary of method Chlorine dioxide reacts with DPD N N diethyl p phenylenediamine to the extent of one fifth of its total available chlorine content corresponding to reduction of chlorine dioxide to chlorite The resulting pink color intensity is proportional to the ClO in the sample Chlorine interference is eliminated by adding glycine which converts free chlorine to chloroaminoacetic acid but has no effect on chlorine dioxide at the test pH Test results ar
4. as regulated by Federal RCRA for arsenic D004 Refer to a current MSDS for proper disposal instructions Sample collection preservation and storage Analyze samples for chlorine dioxide immediately after collection Chlorine dioxide is a strong oxidizing agent and is unstable in natural waters It reacts rapidly with various inorganic compounds but oxidizes organic compounds more slowly Many factors including reactant concentrations sunlight pH temperature and salinity influence decomposition of chlorine dioxide in water Avoid plastic containers since these may have a large chlorine dioxide demand Pretreat glass sample containers to remove any chlorine or chlorine dioxide demand by soaking in a dilute bleach solution 1 mL commercial bleach to 1 liter of deionized water for at least one hour Rinse thoroughly with deionized or distilled water If sample containers are rinsed thoroughly with deionized or distilled water after use only occasional pretreatment is necessary A common error in testing for chlorine dioxide is not obtaining a representative sample If sampling from a tap let the water flow for at least 5 minutes to ensure a representative sample Let the container overflow with the sample several times then cap the sample containers so there is no headspace air above the sample If sampling with a sample cell rinse the cell several times with the sample then carefully fill to the 10 mL mark Perform the chlorine dioxide an
5. e Keep the tip any undissolved powder to the cell holder immersed while the Ampul settle fills completely Interferences Table 2 Interfering substances Interfering substance Interference level Greater than 150 mg L CaCO3 May not develop full color or color may fade instantly Neutralize Acidity to pH 6 7 with 1 N Sodium Hydroxide Determine amount to be added on a separate sample aliquot then add the same amount to the sample being tested Correct for volume addition Greater than 250 mg L CaCO Color may not develop fully or may fade instantly Neutralize to Alkalinity pH 6 7 with 1 N Sulfuric Acid Determine amount to be added on a separate sample aliquot then add the same amount to the sample being tested Correct for the volume addition Bromine Bro Interferes at all levels Chlorine Cl May interfere at levels greater than 6 mg L Additional glycine may be able to compensate for this interference Chloramines organic May interfere High levels of most flocculating agents can be tolerated This tolerance is decreased if chlorine Flocculating agents is present See the information about metals in this table In the presence of 0 6 mg L Clo Al SQq 3 lt 500 mg L and FeCl lt 200 mg L may be tolerated Hardness No effect at less than 1000 mg L as CaCO3 lodine l gt Interferes at all levels Oxidized manganese interferes at all levels Oxidized chromium interferes at levels greater than 2 mg L To remove t
6. e measured at 530 nm Consumables and replacement items Required reagents Description Quantity Test Unit Catalog number Chlorine Dioxide DPD Glycine Reagent Set 100 tests includes 2770900 1 DPD Free Chlorine Reagent Powder Pillows 10 mL 1 100 pkg 2105569 1 Glycine Reagent 4 drops 29 mL 2762133 OR Chlorine Dioxide DPD Glycine AccuVac Ampul Reagent Set 25 tests includes 2771000 1 DPD Free Chlorine Reagent AccuVac Ampuls 1 25 pkg 2902025 1 Glycine Reagent 16 drops 29 mL 2762133 Required apparatus Description Quantity Unit Catalog number AccuVac Snapper 1 each 2405200 Beaker 50 mL 1 each 50041H Stopper for 18 mm tube 1 6 pkg 173106 Sample cell 10 mL round 25 x 54 mm 1 each 2122800 Sample cell 10 mL round 25 x 60 mm 1 6 pkg 2427606 Sample cell 10 mL square matched pair 2 2 pkg 2495402 Recommended standards Description Unit Catalog number Chlorine Standard Solution 10 mL Voluette Ampule 50 75 mg L 16 pkg 1426810 Voluette Ampule Breaker for 10 mL ampules each 2196800 Water organic free 500 mL 2641549 Chlorine Dioxide Page 6 of 8 Optional reagents and apparatus Chlorine Dioxide Description Unit Catalog number AccuVac Vials for sample blanks 25 pkg 2677925 DPD Free Chlorine Reagent Powder Pillows 10 mL 1000 pkg 2105528 DPD Free Chlorine Reagent Powder Pillows 10 mL 300 pkg 2105503 Potassium lodide 30 g L 100 mL 34332 Sodium Arsenite 5 g L 100 mL 104732
7. ent The display will show 0 00 mg L ClO 9 Within one minute of adding the DPD reagent wipe the sample cell and insert it into the cell holder 6 Add four drops of Glycine Reagent to the sample Swirl to mix Read 10 READ the results in mg L ClO DPD method AccuVac Ampuls 7 Add the contents of one DPD Free Chlorine Powder Pillow to the prepared sample cell Swirl the sample for 20 seconds to mix HRS MIN 8 Wait 30 seconds for any undissolved powder to settle Immediately proceed to step 9 Stored Programs 77 Chlor Diox DPD AV Start 1 Select the test Insert an adapter if required see nstrument specific information Refer to the user manual for orientation a p gt om 2 Blank Preparation Filla round sample cell with 10 mL of sample 3 Wipe the blank and insert it into the cell holder ZERO the instrument The display will show 0 00 mg L ClO 4 Prepared Sample Fill a 50 mL beaker with 40 mL of sample Add 16 drops of Glycine Reagent to the sample in the beaker Swirl gently to mix Chlorine Dioxide Page 3 of 8 Chlorine Dioxide DPD method AccuVac Ampuls continued Read 5 Filla DPD Free 6 Quickly invert the 7 Within one minute of 8 READ the results in Chlorine Reagent Ampul several times to adding the sample wipe mg L ClOo AccuVac Ampul with mix Wait 30 seconds for the Ampul and insert it into sampl
8. he interferences 1 Adjust sample pH to 6 7 Manganese oxidized Add 3 drops Potassium lodide 30 g L to a 25 mL sample Mn4 Mn or Mix and wait one minute Chromium oxidized Cr 4 Add 3 drops Sodium Arsenite 2 5 g L and mix Analyze 10 mL of the treated sample as described in the procedure Subtract the result of this test from the original analysis to obtain the correct chlorine dioxide concentration Chlorine Dioxide Page 4 of 8 Chlorine Dioxide Table 2 Interfering substances continued Interfering substance Interference level Various metals may interfere by combining with the glycine needed to remove the chlorine interference Metal interference is limited except when chlorine is present In the presence of Metals 0 6 mg L Cl both copper gt 10 mg L and nickel gt 50 mg L interfere Other metals may also interfere depending on their ability to prevent glycine from reacting with any Cl in the sample It may be necessary to add more glycine to overcome this interference M h Causes a gradual drift to higher readings When read within 1 minute after reagent addition A 3 mg L monochloramine causes less than a 0 1 mg L CIO increase in the reading Interferes at levels greater than 1 5 mg L Extreme sample pH Adjust to pH 6 7 Highly buffered samples Adjust to pH 6 7 1 See Optional reagents and apparatus 2 Samples treated with sodium arsenite for interferences will be hazardous waste
9. lor will develop if chlorine dioxide is present If the chlorine dioxide concentration in the sample exceeds the upper limit of the test the color may fade or the sample may turn yellow Dilute the sample with high quality water that is chlorine demand free and repeat the test Some loss of chlorine dioxide may occur Multiply the result by the appropriate dilution factor Chlorine Dioxide Page 1 of 8 Chlorine Dioxide Collect the following items Description Quantity Powder Pillow Test DPD Free Chlorine powder pillow 10 mL Glycine Reagent Sample cells see nstrument specific information Stopper for 18 mm tube AccuVac Test DPD Free Chlorine Reagent AccuVac Ampuls 1 Glycine Reagent 16 drops Beaker 50 mL Sample Cell see nstrument specific information Stopper for 18 mm tube See Consumables and replacement items for reorder information DPD method powder pillows Stored Programs o m 76 Chiro Diox DPD Start 1 Select the test 2 Blank Preparation 3 Prepared Sample 4 Wipe the blank and Insert an adapter if Fill a sample cell with 10 Fill a second sample cell insert it into the cell holder required see Instrument mL of sample Close the with 10 mL of sample sample cell Close the sample cell specific information Refer to the user manual for orientation Chlorine Dioxide Page 2 of 8 DPD method powder pillows continued Chlorine Dioxide Zero 5 ZERO the instrum
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