ASTM D3557-2002(2007)e1 Standard Test Methods for Cadmium in Water《水中镉含量的标准试验方法》.pdf

1、Designation: D 3557 02 (Reapproved 2007)e1Standard Test Methods forCadmium in Water1This standard is issued under the fixed designation D 3557; 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

2、parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.e1NOTEEditorial changes were made throughout in September 2007.1. Scope1.1 These test methods cover the determination of dissolvedand total recoverable cadm

3、ium in water and wastewater byatomic-absorption spectrophotometry and differential pulseanodic stripping voltammetry.2Four test methods are includedas follows:ConcentrationRangeSectionsTest Method AAtomic Absorption,Direct0.05 to 2.0mg/L7to15Test Method BAtomic Absorption,Chelation-Extraction5to200g

4、/L 16to24Test Method CDifferential PulseAnodic Stripping Voltammetry1to100g/L 25to34Test Method DAtomic Absorption,Graphite Furnace2to10g/L 35to431.2 Test Method B can be used to determine cadmium inbrines. It is the users responsibility to ensure the validity ofthese test methods for waters of unte

5、sted matrices.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 determine the applica-bility of regulatory limitations prior to use.2

6、. Referenced Documents2.1 ASTM Standards:3D 858 Test Methods for Manganese in WaterD 1066 Practice for Sampling SteamD 1068 Test Methods for Iron in WaterD 1129 Terminology Relating to WaterD 1192 Guide for Equipment for Sampling Water andSteam in Closed Conduits4D 1193 Specification for Reagent Wat

7、erD 1687 Test Methods for Chromium in WaterD 1688 Test Methods for Copper in WaterD 1691 Test Methods for Zinc in WaterD 1886 Test Methods for Nickel in WaterD 2777 Practice for Determination of Precision and Bias ofApplicable Test Methods of Committee D19 on WaterD 3370 Practices for Sampling Water

8、 from Closed ConduitsD 3558 Test Methods for Cobalt in WaterD 3559 Test Methods for Lead in WaterD 3919 Practice for Measuring Trace Elements in Water byGraphite Furnace Atomic Absorption SpectrophotometryD 4841 Practice for Estimation of Holding Time for WaterSamples Containing Organic and Inorgani

9、c ConstituentsD 5810 Guide for Spiking into Aqueous SamplesD 5847 Practice for Writing Quality Control Specificationsfor Standard Test Methods for Water Analysis3. Terminology3.1 Definitions: For definitions of terms used in these testmethods, refer to Terminology D 1129.3.2 Definitions of Terms Spe

10、cific to This Standard:3.2.1 spiking solutionthe standard solution added to thepolarographic cell that is used to quantitate the sample.3.2.2 stripping peak potentialthe applied potential versusSCE at which the stripping peak current is a maximum.3.2.3 SCEsaturated calomel electrode.3.2.4 stripping

11、peak signalthe current measured at thestripping peak maximum for a metal.4. Significance and Use4.1 The test for cadmium is necessary because it is atoxicant and because there is a limit specified for cadmium inpotable water in the National Interim Primary Drinking WaterRegulations. This test serves

12、 to determine whether the cad-mium content of potable water is above or below the accept-able limit.1These test methods are under the jurisdiction of ASTM Committee D19 onWater and are the direct responsibility of Subcommittee D19.05 on InorganicConstituents in Water.Current edition approved Aug. 1,

13、 2007. Published September 2007. Originallyapproved in 1977. Last previous edition approved in 2002 as D 3557 02.2Platte, J.A., and Marcy, V. M., “ANew Tool for the Water Chemist,” IndustrialWater Engineering, May 1965.3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact A

14、STM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.4Withdrawn.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5. Purity of Rea

15、gents5.1 Reagent grade chemicals shall be used in all tests.Unless otherwise indicated, it is intended that all reagents shallconform to the specifications of the Committee on AnalyticalReagents of the American Chemical Society.5Other gradesmay be used, provided it is first ascertained that the reag

16、ent isof sufficiently high purity to permit its use without lesseningthe accuracy of the determination.5.2 Unless otherwise indicated, references to water shall beunderstood to mean reagent water conforming to SpecificationD 1193, Type I. Other reagent water types may be used,provided it is first as

17、certained that the water is of sufficientlyhigh purity to permit its use without adversely affecting thebias and precision of the test method. Type II water wasspecified at the time of round-robin testing of this test method.6. Sampling6.1 Collect the samples in accordance with the applicableASTM st

18、andard as follows: Practices D 3370, Practice D 1066,and Specification D 1192.6.2 Samples shall be preserved with HNO3(sp gr 1.42) to apH of 2 or less immediately at the time of collection, normallyabout 2 mL/L of HNO3. If only dissolved cadmium is to bedetermined, the sample shall be filtered throu

19、gh a 0.45-m (No.325) membrane filter before acidification. The holding time forsamples may be calculated in accordance with Practice D 4841.TEST METHOD AATOMIC ABSORPTION, DIRECT7. Scope7.1 This test method covers the determination of dissolvedand total recoverable cadmium in most waters and wastewa

20、-ters.7.2 This test method is applicable in the range from 0.05 to2.0 mg/L of cadmium. The range may be extended to concen-trations greater than 2.0 mg/L by dilution of the sample.7.3 This test method has been used successfully withreagent grade water, river water, wastewater, ground water, tapwater

21、, lake water, and refinery effluent. The information onprecision and bias may not apply to other water. It is the usersresponsibility to ensure the validity of this test method forwaters of other matrices.8. Summary of Test Method8.1 Cadmium is determined by atomic absorption spectro-photometry. Dis

22、solved cadmium is determined by aspirating aportion of the filtered sample directly with no pretreatment.Total recoverable cadmium is determined by aspirating thesample following hydrochloric-nitric acid digestion and filtra-tion. The same digestion procedure may be used to determinetotal recoverabl

23、e nickel (Test Methods D 1886), chromium(Test Methods D 1687), cobalt (Test Methods D 3558), copper(Test Methods D 1688), iron (Test Methods D 1068), lead (TestMethods D 3559), manganese (Test Methods D 858), and zinc(Test Methods D 1691).9. Interferences9.1 Calcium concentrations above 1000 mg/L su

24、ppress thecadmium absorption.At 2000 mg/L of calcium the suppressionis 19 %.9.2 Sodium, potassium, sulfate, and chloride (9000 mg/Leach), magnesium (4500 mg/L), iron (4000 mg/L), nitrate (100mg/L), and nickel, lead, copper, zinc, cobalt, and chromium(10 mg/L each), do not interfere.9.3 Background co

25、rrection or a chelation-extraction proce-dure (see Test Method B) may be necessary to determine lowlevels of cadmium in some waters.NOTE 1Instrument manufacturers instructions for use of the specificcorrection technique should be followed.10. Apparatus10.1 Atomic Absorption Spectrophotometer, for us

26、e at228.8 nm.NOTE 2The manufacturers instructions shall be followed for allinstrumental parameters. A wavelength other than 228.8 nm may be usedif it has been determined to be equally suitable.10.2 Cadmium Light SourceEither cadmium hollow-cathode lamps or multielement hollow-cathode lamps, orelectr

27、odeless-discharge lamps.10.3 Pressure-Reducing ValvesThe supplies of fuel andoxidant shall be maintained at pressures somewhat higher thanthe controlled operating pressure of the instrument by suitablevalves.11. Reagents and Materials11.1 Cadmium Solution, Stock (1 mL = 1.0 mg Cd)Dissolve 1.000 g of

28、 cadmium metal in a minimum quantity ofHNO3(sp gr 1.42) and dilute to 1 L.11.2 Cadmium Solution, Standard (1 mL = 0.1 mg Cd)Dilute 100.0 mL of the cadmium stock solution and 1 mL ofHNO3(sp gr 1.42) to 1000 mL with water.11.3 Hydrochloric Acid (sp gr 1.19)Concentrated hydro-chloric acid (HCl).NOTE 3I

29、f the reagent blank concentration is greater than the methoddetection limit, distill the HCl or use spectrograde acid. (WarningWhenHCl is distilled, an azeotropic mixture is obtained (approximately 6 NHCl). Therefore, whenever concentrated HCl is specified for the prepara-tion of a reagent or in the

30、 procedure, use double the volume specified ifdistilled acid is used.)11.4 Nitric Acid (sp gr 1.42)Concentrated nitric acid(HNO3).NOTE 4If the reagent blank concentration is greater than the methoddetection limit, distill the HNO3or use a spectrograde acid.11.5 Nitric Acid (1 + 499)Add 1 volume of H

31、NO3(sp gr1.42) to 499 volumes of water.11.6 Oxidant:11.6.1 Air, which has been passed through a suitable filter toremove oil, water, and other foreign substances is the usualoxidant.5Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestion

32、s 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.D 3557 02 (2007)e1211.7 Fuel:11.7.1

33、 AcetyleneStandard, commercially available acety-lene is the usual fuel. Acetone, always present in acetylenecylinders, can affect analytical results. The cylinder should bereplaced at 50 psig (345 kPa). (Warning“Purified” gradeacetylene containing a special proprietary solvent rather thanacetone sh

34、ould not be used with poly(vinyl chloride) tubing asweakening of the tubing walls can cause a potentially hazard-ous situation.)12. Standardization12.1 Prepare 100 mL each of a blank and at least fourstandard solutions to bracket the expected cadmium concen-tration range of the samples to be analyze

35、d by diluting thestandard cadmium solution (11.2) with HNO3(1 + 499). Pre-pare the standards each time the test is to be performed.12.2 When determining total recoverable cadmium, add 0.5mL of HNO3(sp gr 1.42) to each blank and standard solutionand proceed as directed in 13.2 through 13.4. After the

36、digestion of the blank and standard solutions has been com-pleted in 13.4, return to 12.3 to complete the standardizationfor total recoverable determinations. When determining dis-solved cadmium, proceed with 12.3.12.3 Aspirate the blank and standards and record the instru-ment readings. Aspirate HN

37、O3(1 + 499) between each stan-dard.12.4 Prepare an analytical curve by plotting the absorbanceversus the concentration for each standard on the instrumentsoftware. Alternatively, read directly in concentration if thiscapability is provided with the instrument.13. Procedure13.1 Measure 100.0 mL of a

38、well-mixed acidified sampleinto a 125-mL beaker or flask.NOTE 5If only dissolved cadmium is to be determined, start with13.5.13.2 Add 5 mL of HCl (sp gr 1.19) to each sample.13.3 Heat the samples on a steam bath or hotplate in awell-ventilated hood until the volume has been reduced to 15to 20 mL, ma

39、king certain that the samples do not boil.NOTE 6For samples containing appreciable amounts of suspendedmatter or dissolved solids, the amount of reduction in volume is left to thediscretion of the analyst.13.4 Cool and filter the samples through a suitable filtersuch as fine-textured, acid-washed, a

40、shless, paper into 100-mLvolumetric flasks. Wash the filter paper two or three times withwater and adjust to volume.13.5 Aspirate each filtered and acidified sample and deter-mine its absorbance or concentration at 228.8 nm. AspirateHNO3(1 + 499) between each sample.14. Calculation14.1 Calculate the

41、 concentration of cadmium in the sample,in milligrams per litre, using the analytical curve prepared in12.4.15. Precision and Bias615.1 The precision of this test method was tested by 17laboratories in reagent water, river water, wastewater, groundwater, tap water, lake water, and refinery effluent.

42、 The overallbias and precision of this test method, within its designatedrange, varies with the quantity being measured in accordancewith Table 1.15.2 These data may not apply to waters of the matrices,therefore, it is the responsibility of the analyst to ensure thevalidity of the test method in oth

43、er matrices.15.3 Precision and bias for this test method conforms toPractice D 2777 77, which was in place at the time ofcollaborative testing. Under the allowances made in 1.4 ofPractice D 2777 06, these precision and bias data meetexisting requirements for interlaboratory studies of CommitteeD19 t

44、est methods.TEST METHOD BATOMIC ABSORPTION,CHELATION-EXTRACTION16. Scope16.1 This test method covers the determination of dissolvedand total recoverable cadmium in most waters and brines.16.2 This test method is applicable in the range from 5 to200 g/L of cadmium. The range may be extended to concen

45、-trations greater than 200 g/L by dilution of the sample.16.3 This test method has been used successfully withreagent grade water, river water, wastewater, ground water, tapwater, lake water, and refinery effluent. The information onprecision and bias may not apply to other water.16.4 It is the resp

46、onsibility of the analyst to determine theacceptability of this test method when analyzing other matri-ces.17. Summary of Test Method17.1 Cadmium is determined by atomic absorption spectro-photometry. The element, either dissolved or total recoverable,is chelated with pyrrolidine dithiocarbamic acid

47、 and extractedwith chloroform. The extract is evaporated to dryness, treatedwith hot nitric acid to destroy organic matter, dissolved inhydrochloric acid, and diluted to a specified volume with water.A portion of the resulting solution is then aspirated into theair-acetylene flame of the spectrophot

48、ometer. The digestion6Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR:D19-1030.TABLE 1 Determination of Bias and Precision for Cadmium byAtomic Absorption, DirectAmount Added,mg/LAmountFound, mg/LST, mg/L SO, mg/L % BiasStatistic

49、allySignificant,95 % LevelReagent Water0.20 0.200 0.033 0.033 0.0 No0.60 0.592 0.034 0.026 1.3 No1.60 1.521 0.111 0.061 4.9 YesWater of Choice0.20 0.200 0.033 0.033 0.0 No0.60 0.589 0.040 0.026 1.8 No1.60 1.511 0.114 0.061 5.6 YesD 3557 02 (2007)e13procedure summarized in 8.1 is used to determine totalrecoverable cadmium. The same chelation-extraction proce-dure may be used to determine nickel (Test Methods D 1886),cobalt (Test Methods D 3558), copper (Test Methods D 1688),iron (Test Methods D 1068), lead (Test Methods D 3559), andzinc (