ASTM E506-1998(2003) Standard Test Method for Mercury in Liquid Chlorine《液氯中汞含量的试验方法》.pdf

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1、Designation: E 506 98 (Reapproved 2003)Standard Test Method forMercury in Liquid Chlorine1This standard is issued under the fixed designation E 506; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A numbe

2、r in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method2covers the determination of mercuryin liquid chlorine with a lower limit of detection of 0.1 ppb.1.2 This standard does no

3、t 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 determine the applica-bility of regulatory limitations prior to use. Specific precau-tionary statements are

4、given in Sections 7, 6.3, 6.4, 6.5, andNote 2.1.3 Review the current material safety data sheet (MSDS)for detailed information concerning toxicity, first-aid proce-dures, and safety precautions.2. Referenced Documents2.1 ASTM Standards:D 1193 Specification for Reagent Water3E 180 Practice for Determ

5、ining the Precision of ASTMMethods for Analysis and Testing of Industrial Chemicals4E 200 Practice for Preparation, Standardization, and Stor-age of Standard and Reagent Solutions for ChemicalAnalysis43. Summary of Test Method3.1 Liquid chlorine samples are taken in chilled glass flasks,then allowed

6、 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 of mercury from the aqueous solution on standing. Foranalysis, an aliquot of the acidic aqueous solution is boiledwith

7、 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 air stream, is determined using an atomic absorptionspectrophotometer.4. Significance and Use4.1 This test method was

8、developed primarily for thedetermination of traces 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.55.2 Mercury Hollow Cathode Lamp, primary line 253.7 nm

9、.5.3 Absorption Cell, 10-cm path length with quartz win-dows.5,65.4 Gas Washing Bottle, 125 mL, with extra-coarse frittedbubbler.5,7The bottle has a calibration line drawn at the 60-mLmark.5.5 Stopcock, 3-way, with plug of TFE-fluorocarbon.5,85.6 Gas Washing Bottle, 125-mL without frit.95.7 Drying T

10、ube.101This test method is under the jurisdiction of ASTM Committee E15 onIndustrial and Specialty Chemicalsand is the direct responsibility of SubcommitteeE15.02 on Product Standards.Current edition approved Apr. 10, 2003. Published May 2003. Originallyapproved iin 1973. Last previous edition appro

11、ved iin 1998 as E 506 98.2Analytical 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

12、, Dow Chemical of Canada, Ltd., Sarnia, Ontario,Canada.“Determination of Mercury in Liquid Chlorine,” CSAL-M72.4, Feb. 25, 1972,Anaytical Laboratory, Dow Chemical of Canada, Ltd., Sarnia, Ontario, Canada.Chlorine Institute Reference No. MIR-104.3Annual Book of ASTM Standards, Vol 11.01.4Annual Book

13、of ASTM Standards, Vol 15.05.5The sole source of supply of the Beckman 10in. recorder Model No. 100502known to the committee at this time is Beckman Instruments Inc., 2500 HarborBlvd., Fullerton, CA 92634. If you are aware of alternative suppliers, please providethis information to ASTM Internationa

14、l Headquarters. Your comments will receivecareful consideration at a meeting of the responsible technical committee1, whichyou may attend.6The sole source of supply of the Beckman 75144 known to the committee atthis time is Beckman Instruments Inc., 2500 Harbor Blvd., Fullerton, CA 92634. I7The sole

15、 source of supply of the Corning 31770 (125 EC) known to thecommittee at this time is Fisher Scientific, 711 Forbes Ave., Pittsburgh, PA15219-4785. I8The sole source of supply of the Corning 7382 known to the committee at thistime is Fisher Scientific, 711 Forbes Ave., Pittsburgh, PA 15219-4785.9Cor

16、ning 1760, available from Fisher Scientific, 711 Forbes Ave., Pittsburgh, PA15219-4785, or equivalent has been found suitable.10The sole source of supply of the Corning 7775 known to the committee at thistime is Fisher Scientific, 711 Forbes Ave., Pittsburgh, PA 15219-4785.1Copyright ASTM Internatio

17、nal, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5.8 Flow Meter, capable of measuring and maintaining aflow of 1.5 standard ft3/h (42.5 L/h).115.9 Large Dewar Flasks, two, with sufficient capacity tohold a 500-mL flask and a large volume of dry ice coolingmixt

18、ure.5.10 Flexible Connection.5,125.11 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 303 atomic absorption spectrophotom-eter equipped with a 10-cm absorption cell.

19、 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 in instrumentgeometry, cell length, sensitivity, and mode of response measurement

20、 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 Analytical Reagents of the AmericanChemical Society, where such specifications are av

21、ailable.13Blanks 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 conforming to Specification D 1193.6.3 Aqua RegiaCarefully add 10 mL of concentratedHNO3

22、(sp gr 1.42) to 30 mL of concentrated HCl (sp gr 1.19)in a 100-mL beaker. 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 concentratedHNO3(sp gr 1.42) into a

23、 250-mL volumetric flask containingabout 150 mL of water. Dilute to volume with water and mixwell. (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 so

24、lution.)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. Replenish the dryice when necessary. See the MSDS sheet for dichloromethanebefor

25、e using this material.6.7 Hydroxylamine Hydrochloride Solution (100 g/L)SeePractice E 200. This reagent is dispensed with a droppingbottle.6.8 Mercury Standard Solution (50 g Hg/mL)As pre-pared in Practice E 200.6.9 Mercury Standard Solution (10 g Hg/mL)Pipet 10mL of the standard mercury solution co

26、ntaining 50 g Hg/mLinto a 50-mL volumetric flask, acidify with 5 mL of 1 + 4H2SO4and dilute to volume with water. Mix well. Prepare freshdaily.6.10 Mercury Standard Solution (1 g Hg/mL)Pipet 10mL of the standard mercury solution containing 10 g Hg/mLinto a 100-mL volumetric flask, acidify with 5 mL

27、1 + 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 until completelydissolved. Allow the solution to stand overnight and filt

28、er.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 mL of warm concentrated HCl(sp gr 1.19). Add 160 mL of water when all the stannouschloride has dissolved. Allow the solution to sta

29、nd overnightand filter. Mix and store in a 250-mL reagent bottle. Preparefresh once a week. A piece of metallic tin in the bottle allowslonger term storage 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 sk

30、in 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 quickly.7.2 Aqua regia contains both HNO3and HCl, which willcause seve

31、re 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 in ahood or with similar ventilation. This solution is unstable and

32、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 water.7.4 Chlorine is a corrosive and toxic material. A well-ventilated f

33、ume 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 and the operation of the sampling system. Personnelshould be equipped with

34、monogoggles, gloves (if desired), anda respirator. Sampling should be done in a well-ventilated areaor in a hood.7.6 The analysis should be attempted only by persons whoare thoroughly familar with the handling of chlorine, and evenan experienced person should not work alone. The operatormust be prov

35、ided with adequate eye protection and a respirator.Splashes of liquid chlorine destroy clothing and, if suchclothing is next to the skin, will produce irritations and burns.11Brooks Tube P-2-15A with saphire float, available from Brooks InstrumentDiv., Emerson Electric Co., 407 West Vine St., Hatfie

36、ld, PA 19440, or equivalent hasbeen found suitable.12The sole source of supply of Tygon known to the committee at this time isFisher Scientific, 711 Forbes Ave., Pittsburgh, PA 15219-4785.13Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For sug

37、gestions 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.E 506 98 (2003)27.7 When sam

38、pling 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 and acceptablemanner. If chlorine cannot be disposed of

39、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 excess heatingby choosing a sufficiently large volume of cau

40、stic 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 chlorine is inhaled, first aid should besummoned immediate

41、ly 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 dichloromethane-dry icemixture.8.3 Assemble the sampling

42、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 chlorineto flow through the sampling system into the flask. This

43、 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 and acceptable manner.8.8 Attach the delivery system to a

44、 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 mixture.NOTE 2Except for properly designed cylinders, never

45、completelystopper a vessel containing liquid chlorine. A vent 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 mixture and allowthem to evaporate to dryness into a chlori

46、ne absorption systemor some other type of enviornmentally 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. Swirl to assurecomplete solution of the residue. Add

47、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)ina 50-mL volumetric flask, dilute to volume with water, and mixwell.9. Calibration9.1 Care must be taken to avoid contamin

48、ation 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 spectrophotometer and adjust the air flow rate to 1.5standard f

49、t3/h or 42.5 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.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 expansion 13 for 0.05 to 2 g Hg 33 for 0.01 to 0.5 g HgCell 10 cm pathlength with quartz windowsOperating mode absorbance9.4 Allow the base line to s