ASTM E506-17a Standard Test Method for Mercury in Liquid Chlorine.pdf

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1、Designation: E506 17aStandard Test Method forMercury in Liquid Chlorine1This standard is issued under the fixed designation E506; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses in

2、dicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This test method2covers the determination of mercuryin liquid chlorine with a lower limit of detection of 0.1 g/L.1.2 Review the current Safety Data Sheet (SD

3、S) for detailedinformation concerning toxicity, first-aid procedures, andsafety precautions.1.3 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.4 This standard does not purport to address all of thesafety concerns, if any, ass

4、ociated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. Specific precau-tionary statements are given in Sections 7, 6.3, 6.4, 6.5, andNote 2.1.5 This inte

5、rnational standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT)

6、Committee.2. Referenced Documents2.1 ASTM Standards:3D1193 Specification for Reagent WaterD6809 Guide for Quality Control and Quality AssuranceProcedures for Aromatic Hydrocarbons and Related Ma-terialsE180 Practice for Determining the Precision of ASTMMethods for Analysis and Testing of Industrial

7、and Spe-cialty Chemicals (Withdrawn 2009)4E200 Practice for Preparation, Standardization, and Storageof Standard and Reagent Solutions for Chemical Analysis3. Summary of Test Method3.1 Liquid chlorine samples are taken in chilled glass flasks,then allowed to evaporate slowly to dryness. The mercury

8、isleft in the residue. The residue is dissolved in dilute nitric acidand diluted to volume. The addition of nitric acid prevents anyloss of mercury from the aqueous solution on standing. Foranalysis, an aliquot of the acidic aqueous solution is boiledwith excess permanganate to remove interfering ma

9、terials. Themercuric ions are then reduced to metallic mercury withstannous chloride. The solution is aerated and the mercury,now in the air stream, is determined using an atomic absorptionspectrophotometer.4. Significance and Use4.1 This test method was developed primarily for thedetermination of t

10、races of mercury in chlorine produced by themercury-cell process.5. Apparatus5.1 Atomic Absorption Spectrophotometer, equipped withmounting to hold absorption cell and a fast response (0.5 s)recorder.5.2 Mercury Hollow Cathode Lamp, primary line 253.7 nm.5.3 Absorption Cell, 10-cm path length with q

11、uartz win-dows.5.4 Gas Washing Bottle, 125 mL, with extra-coarse frittedbubbler. The bottle has a calibration line drawn at the 60-mLmark.5.5 Stopcock, 3-way, with plug of TFE-fluorocarbon.5.6 Gas Washing Bottle, 125-mL without frit.1This test method is under the jurisdiction of ASTM Committee D16 o

12、nAromatic, Industrial, Specialty and Related Chemicals and is the direct responsi-bility of Subcommittee D16.16 on Industrial and Specialty Product Standards.Current edition approved July 1, 2017. Published July 2017. Originally approvedin 1973. Last previous edition approved in 2017 as E506 17. DOI

13、: 10.1520/E0506-17a.2Analytical Methods for Atomic Absorption Spectrophotometry, Perkin-ElmerLtd., September 1968.“Determination of Mercury in Effluents and Process Streams from a Mercury-Cell Chlorine Plant (Atomic Absorption Flameless Method)” CAS-AM-70.13, June23, 1970, Analytical Laboratory, Dow

14、 Chemical of Canada, Ltd., Sarnia, Ontario,Canada.“Determination of Mercury in Liquid Chlorine,” CSAL-M72.4, Feb. 25, 1972,Analytical Laboratory, Dow Chemical of Canada, Ltd., Sarnia, Ontario, Canada.Chlorine Institute Reference No. MIR-104.3For referenced ASTM standards, visit the ASTM website, www

15、.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.4The last approved version of this historical standard is referenced onwww.astm.org.*A Summary of Changes section appear

16、s at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principle

17、s for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.15.7 Drying Tube.5.8 Flow Meter, capable of measuring and maintaining aflow of 42.5 L/h.5.9 Large Dewar Flasks, two, with sufficient capacity

18、 tohold a 500-mL flask and a large volume of dry ice coolingmixture.5.10 Flexible Tygon or equivalent Connection.5.11 Stainless Steel Compression Nut.5.12 Two-Hole Rubber Stopper.5.13 Fluorocarbon Tubing.NOTE 1The procedure, as described in this test method, was devel-oped using a Perkin-Elmer Model

19、 303 atomic absorption spectrophotom-eter equipped with a 10-cm absorption cell. Any other equivalent atomicabsorption spectrophotometer may be used as well as one of the manycommercial instruments specifically designed for measurement of mer-cury by flameless atomic absorption. However, variation i

20、n instrumentgeometry, cell length, sensitivity, and mode of response measurement mayrequire appropriate modifications of the operating parameters.6. Reagents6.1 Purity of ReagentsUnless otherwise indicated, it isintended that all reagents should conform to the specificationsof the Committee on Analy

21、tical Reagents of the AmericanChemical Society, where such specifications are available.5Blanks should be run on all reagents to assure a negligiblemercury content.6.2 Purity of WaterUnless otherwise indicated, referencesto water shall be understood to mean Type II or Type IIIreagent water conformin

22、g to Specification D1193.6.3 Aqua RegiaCarefully add 10 mL of concentratedHNO3(sp gr 1.42) to 30 mL of concentrated HCl (sp gr 1.19)in a 100-mLbeaker. Let the mixture stand for 5 min before use.This mixture is unstable and should not be stored. (WarningUse goggles when preparing or using this soluti

23、on.)6.4 Nitric Acid (1+9)Pipet 25 mL of concentrated HNO3(sp gr 1.42) into a 250-mL volumetric flask containing about150 mL of water. Dilute to volume with water and mix well.(WarningUse goggles when preparing this solution.)6.5 Sulfuric Acid (1+4)Add slowly with stirring 200 mLof concentrated H2SO4

24、(sp gr 1.84) to 800 mL of water.(WarningUse goggles when preparing this solution.)6.6 Cooling Mixture for Dewar FlasksFill two thirds ofthe Dewar flask with dichloromethane. Add dry ice slowly,allowing time for the solution to cool, until there is nosublimation of dry ice on further addition. Replen

25、ish the dryice when necessary. See the SDS sheet for dichloromethanebefore using this material.6.7 Hydroxylamine Hydrochloride Solution (100 g/L)SeePractice E200. This reagent is dispensed with a droppingbottle.6.8 Mercury Standard Solution (50 g Hg/mL)As pre-pared in Practice E200.6.9 Mercury Stand

26、ard Solution (10 g Hg/mL)Pipet 10mL of the standard mercury solution containing 50 g Hg/mLinto a 50-mL volumetric flask, acidify with 5 mL of 1 + 4H2SO4and dilute to volume with water. Mix well. Preparefresh daily.6.10 Mercury Standard Solution (1 g Hg/mL)Pipet 10mL of the standard mercury solution

27、containing 10 g Hg/mLinto a 100-mLvolumetric flask, acidify with 5 mL1 + 4 H2SO4and dilute to volume with water. Mix well. Prepare fresh daily.6.11 Potassium Permanganate Solution (40 g/L) (4 %)Weigh 40 g of KMnO4into a 1000-mL beaker. Add about 800mL of water and stir with a mechanical stirrer unti

28、l completelydissolved. Allow the solution to stand overnight and filter.Transfer to a 1000-mL volumetric flask, dilute to volume, andstore in a brown bottle.6.12 Stannous Chloride (10 %)Dissolve 20 g of stannouschloride (SnCl22H2O) in 40 mLof warm concentrated HCl (spgr 1.19). Add 160 mL of water wh

29、en all the stannous chloridehas dissolved. Allow the solution to stand overnight and filter.Mix and store in a 250-mL reagent bottle. Prepare fresh oncea week. A piece of metallic tin in the bottle allows longer termstorage if the bottle is well sealed.7. Safety Precautions7.1 Sulfuric acid will cau

30、se severe burns if allowed to comein contact with any part of the skin or eyes. All spillages mustbe immediately flushed from the skin or eyes with cold water.This acid must always be added slowly to water with adequatestirring since heat is developed and spattering occurs if the acidis added too qu

31、ickly.7.2 Aqua regia contains both HNO3and HCl, which willcause severe burns if allowed to come in contact with any partof the skin or eyes. All spillages must be immediately flushedfrom the skin or eyes with cold water. Vapors produced by aquaregia can cause burns if inhaled. It should be used only

32、 in afume hood or with similar ventilation. This solution is unstableand must not be placed in a stoppered flask or bottle.7.3 Nitric acid will cause severe burns if allowed to come incontact with any part of the skin or eyes. All spillages must beimmediately flushed from the skin or eyes with cold

33、water.7.4 Chlorine is a corrosive and toxic material. A well-ventilated fume hood should be used to house all test equip-ment when this product is analyzed in the laboratory.7.5 Liquid chlorine sampling should be performed only bythose persons thoroughly familiar with the handling of thismaterial an

34、d the operation of the sampling system. Personnelshould be equipped with monogoggles, gloves (if desired), anda respirator. Sampling should be done in a well-ventilated areaor in a fume hood.5Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For s

35、uggestions on the testing of reagents notlisted by the American Chemical Society, see Analar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.E506 17a27.6 The analysis

36、should be attempted only by persons whoare thoroughly familiar with the handling of chlorine, and evenan experienced person should not work alone. The operatormust be provided with adequate eye protection and a respirator.Splashes of liquid chlorine destroy clothing and, if suchclothing is next to t

37、he skin, will produce irritations and burns.7.7 When sampling and working with chlorine out of doors,people downwind from such operation should be warned of thepossible release of chlorine vapors.7.8 It is recommended that means be available for disposalof excess chlorine in an environmentally safe

38、and acceptablemanner. If chlorine cannot be disposed of in a chlorineconsuming process, the chlorine should be discharged into acaustic scrubber containing an appropriate amount of 20 %caustic solution to neutralize all the chlorine. This reaction isexothermic, and care should be taken to avoid exce

39、ss heatingby choosing a sufficiently large volume of caustic solution toserve as a heat sink. When the analysis and sampling regimenrequires an initial purging of chlorine from a container, thepurged chlorine should be similarly handled. Purging to theatmosphere should be avoided.7.9 In the event ch

40、lorine is inhaled, first aid should besummoned immediately and oxygen administered withoutdelay.7.10 Handle all other reagents as recommended by thesupplier.8. Sampling8.1 Soak all 500-mL receiver flasks carefully in 50C aquaregia and rinse with water before use.8.2 Cool two receiver flasks in the d

41、ichloromethane-dry icemixture.8.3 Assemble the sampling apparatus as shown in Fig. 1.8.4 With a respirator ready for immediate use, locate your-self upwind of the receiver flask.8.5 Keeping the receiver flask in the dry ice solution, purgethe sampling system allowing 100 to 200 mL of liquid chlorine

42、to flow through the sampling system into the flask. This purgesany residual mercury deposits from the lines and sample point.8.6 Stop the flow of liquid chlorine.8.7 Cap the waste liquid chlorine flask with an open,one-hole stopper and store in a dry ice bath for disposal in anenvironmentally safe a

43、nd acceptable manner.8.8 Attach the delivery system to a cooled 500-mL receiverflask and fill with liquid chlorine to the 200-mL mark. Othervolumes may be used if desired.8.9 Stop the flow of liquid chlorine.8.10 Cap the flask with an open, one-hole stopper and storein a dichloromethane-dry ice mixt

44、ure.NOTE 2Except for properly designed cylinders, never completelystopper a vessel containing liquid chlorine.Avent must always be presentto relieve the pressure from evaporating liquid chlorine.8.11 Remove the sample of liquid chlorine and waste liquidchlorine from the dichloromethane-dry ice mixtu

45、re and allowthem to evaporate to dryness into a chlorine absorption systemor some other type of environmentally safe and acceptablemanner of chloride disposal. Discard the residue from thewaste chlorine.8.12 Add 10 mL of HNO3(1 + 9) to the flask containing theresidue from the liquid chlorine sample.

46、 Swirl to assurecomplete solution of the residue. Add 25 mL of water andtransfer to a 50-mL volumetric flask. Dilute to volume with thewater used to rinse the flask and mix well.8.13 Prepare a blank consisting of 10 mL of HNO3(1+9)in a 50-mL volumetric flask, dilute to volume with water, andmix well

47、.9. Calibration9.1 Care must be taken to avoid contamination of theapparatus with mercury. Soak all glass apparatus (pipets,beakers, and gas washing bottle) in aqua regia prior to use andrinse thoroughly with water before use.9.2 Connect the apparatus shown in Fig. 2 to the atomicabsorption spectrop

48、hotometer and adjust the air flow rate to42.5 L/h.9.3 Adjust the operating conditions in accordance with themanufacturers recommendations for doing mercury analysisand allow the spectrophotometer to warm up for at least 15 min(see Note 1). Listed below are typical conditions for oneinstrument.Wavele

49、ngth 253.7 nmSlit width (0.65 nm)Lamp current approximately by 10 mARecorder noise suppression 2, giving approximately 90 % of response in 1 sScale expansion 1 for 0.05 to 2 g Hg 3 for 0.01 to 0.5 g HgCell 10 cm pathlength with quartz windowsOperating mode absorbance9.4 Allow the base line to stabilize with stopcock A in theby-pass position and an empty gas washing bottle connected tothe apparatus.FIG. 1 Sampling System for Liquid ChlorineE506 17a39.5 Add 2 mL of 10 % SnCl2solution and 60 mL of waterto the wash bottle and aerate. An abs