ASTM E506-2017 4652 Standard Test Method for Mercury in Liquid Chlorine《液氯中汞含量的标准试验方法》.pdf

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1、Designation: E506 17Standard 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 ind

2、icates 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 The values stated in SI units are to be r

3、egarded asstandard. No other units of measurement are included in thisstandard.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and dete

4、rmine 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 2.1.4 Review the current Safety Data Sheet (SDS) for detailedinformation concerning toxicity, first-aid procedures, andsafety precautions.2. Referenced

5、Documents2.1 ASTM Standards:3D1193 Specification for Reagent WaterE180 Practice for Determining the Precision of ASTMMethods for Analysis and Testing of Industrial and Spe-cialty Chemicals (Withdrawn 2009)4E200 Practice for Preparation, Standardization, and Storageof Standard and Reagent Solutions f

6、or 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 isleft in the residue. The residue is dissolved in dilute nitric acidand diluted to volume. The addition of nitric acid prevents anyloss

7、 of mercury from the aqueous solution on standing. Foranalysis, an aliquot of the acidic aqueous solution is boiledwith excess permanganate to remove interfering materials. Themercuric ions are then reduced to metallic mercury withstannous chloride. The solution is aerated and the mercury,now in the

8、 air stream, is determined using an atomic absorptionspectrophotometer.4. Significance and Use4.1 This test method was developed primarily for thedetermination of traces of mercury in chlorine produced by themercury-cell process.5. Apparatus5.1 Atomic Absorption Spectrophotometer, equipped withmount

9、ing 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 quartz win-dows.5.4 Gas Washing Bottle, 125 mL, with extra-coarse frittedbubbler. The bottle has a calibration line drawn at the 60-mLmar

10、k.5.5 Stopcock, 3-way, with plug of TFE-fluorocarbon.5.6 Gas Washing Bottle, 125-mL without frit.5.7 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 tohold a 500-mL flask and a large volume of dry ice coolingmix

11、ture.5.10 Flexible Tygon or equivalent Connection.5.11 Stainless Steel Compression Nut.5.12 Two-Hole Rubber Stopper.5.13 Fluorocarbon Tubing.1This test method is under the jurisdiction of ASTM Committee D16 onAromatic Hydrocarbons and Related Chemicals and is the direct responsibility ofSubcommittee

12、 D16.16 on Industrial and Specialty Product Standards.Current edition approved March 1, 2017. Published March 2017. Originallyapproved in 1973. Last previous edition approved in 2008 as E506 08. DOI:10.1520/E0506-17.2Analytical Methods for Atomic Absorption Spectrophotometry, Perkin-ElmerLtd., Septe

13、mber 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 Chemical of Canada, Ltd., Sarnia, Ontario,Canada.“Determination of Mercury in Liquid Chlorine,” CSAL-M7

14、2.4, 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.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume i

15、nformation, 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 appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Cons

16、hohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Or

17、ganization Technical Barriers to Trade (TBT) Committee.1NOTE 1The procedure, as described in this test method, was devel-oped using a Perkin-Elmer Model 303 atomic absorption spectrophotom-eter equipped with a 10-cm absorption cell. Any other equivalent atomicabsorption spectrophotometer may be used

18、 as well as one of the manycommercial instruments specifically designed for measurement of mer-cury by flameless atomic absorption. However, variation in instrumentgeometry, cell length, sensitivity, and mode of response measurement mayrequire appropriate modifications of the operating parameters.6.

19、 Reagents6.1 Purity of ReagentsUnless otherwise indicated, it isintended that all reagents should conform to the specificationsof the Committee on Analytical Reagents of the AmericanChemical Society, where such specifications are available.5Blanks should be run on all reagents to assure a negligible

20、mercury content.6.2 Purity of WaterUnless otherwise indicated, referencesto water shall be understood to mean Type II or Type IIIreagent water conforming 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-mLbeake

21、r. 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 solution.)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 volu

22、me 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(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 fl

23、ask with dichloromethane. Add dry ice slowly,allowing time for the solution to cool, until there is nosublimation of dry ice on further addition. Replenish the dryice when necessary. See the SDS sheet for dichloromethanebefore using this material.6.7 Hydroxylamine Hydrochloride Solution (100 g/L)See

24、Practice 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 Standard 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 + 4H

25、2SO4and 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 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

26、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 until completelydissolved. Allow the solution to stand overnight and filter.Transfer to a 1000-mL volumetric flask, dilute to volume, andstore in a brow

27、n 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 when all the stannous chloridehas dissolved. Allow the solution to stand overnight and filter.Mix and store in a 250-mL reagent bottle. Prepare fresh

28、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 cause 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

29、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 quickly.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 spi

30、llages 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 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 caus

31、e 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 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 a

32、nalyzed in the laboratory.7.5 Liquid chlorine sampling should be performed only bythose persons thoroughly familiar with the handling of thismaterial and the operation of the sampling system. Personnelshould be equipped with monogoggles, gloves (if desired), anda respirator. Sampling should be done

33、in a well-ventilated areaor in a fume hood.7.6 The analysis 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

34、 chlorine destroy clothing and, if suchclothing is next to the 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 availabl

35、e for disposalof excess chlorine in an environmentally safe 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 r

36、eaction isexothermic, and care should be taken to avoid excess heating5Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see Analar Standards for LaboratoryChem

37、icals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.E506 172by choosing a sufficiently large volume of caustic solution toserve as a heat sink. When the analysis and sampling regimenrequires an initi

38、al purging of chlorine from a container, thepurged chlorine should be similarly handled. Purging to theatmosphere should be avoided.7.9 In the event chlorine is inhaled, first aid should besummoned immediately and oxygen administered withoutdelay.7.10 Handle all other reagents as recommended by thes

39、upplier.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 dichloromethane-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

40、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 chlorineto 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 liq

41、uid 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 and 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 m

42、ay 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 mixture.NOTE 2Except for properly designed cylinders, never completelystopper a vessel containing liquid chlorine.Avent must always be presentto relieve

43、the pressure from evaporating liquid chlorine.8.11 Remove the sample of liquid chlorine and waste liquidchlorine from the dichloromethane-dry ice mixture and allowthem to evaporate to dryness into a chlorine absorption systemor some other type of environmentally safe and acceptablemanner of chloride

44、 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. 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

45、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.9. Calibration9.1 Care must be taken to avoid contamination of theapparatus with mercury. Soak all glass apparatus (pipets,beakers, and gas washing

46、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 spectrophotometer and adjust the air flow rate to42.5 L/h.9.3 Adjust the operating conditions in accordance with themanufacturers recommendations for doing m

47、ercury analysisand allow the spectrophotometer to warm up for at least 15 min(see Note 1). Listed below are typical conditions for oneinstrument.Wavelength 253.7 nmSlit width (0.65 nm)Lamp current approximately by 10 mARecorder noise suppression 2, giving approximately 90 % of response in 1 sScale e

48、xpansion 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.9.5 Add 2 mL of 10 % SnCl2solution and 60 mL of

49、waterto the wash bottle and aerate. An absorbance peak of less than0.03 % should be obtained at 3 scale expansion. Continuerunning blanks until this is achieved. Consistently higherblanks indicate a contamination problem from dirty glasswareor reagents. Clean the apparatus with aqua regia and preparefresh reagents until a satisfactory blank is obtained.9.6 Prepare at least three standards by pipetting the follow-ing volumes of the 1 g Hg/mL standard into 50-mL beakers.mL of 1 g/mL Standard g Hg in Standard0.1 0.10.2 0.20.5 0.51.0 1.02.0 2.09.7 Dilut