1、Designation: D3557 12D3557 17Standard Test Methods forCadmium in Water1This standard is issued under the fixed designation D3557; 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 These test methods cover the determination of dissolved and total recoverable cadmium in water and wastewater byatomic-absorption spectrophotometry and differ
3、ential pulse anodic stripping voltammetry.2 Section 44 on Quality Control pertainsto these test methods. Four test methods are included as follows:ConcentrationRange SectionsTest Method AAtomic Absorption,Direct0.05 to 2.0mg/L7 to 15Test Method BAtomic Absorption,Chelation-Extraction5 to 200 g/L 16
4、to 24Test Method CDifferential PulseAnodic Stripping Voltammetry1 to 100 g/L 25 to 34Test Method DAtomic Absorption,Graphite Furnace2 to 10 g/L 35 to 43ConcentrationRange SectionsTest Method AAtomic Absorption,Direct0.05 to 2.0mg/L7 to 15Test Method BAtomic Absorption,Chelation-Extraction5 to 200 g/
5、L 16 to 24Test Method CDifferential PulseAnodic Stripping Voltammetry1 to 100 g/L 25 to 34Test Method DAtomic Absorption,Graphite Furnace2 to 10 g/L 35 to 431.2 Test Method B can be used to determine cadmium in brines. It is the users responsibility to ensure the validity of these testmethods for wa
6、ters of untested matrices.1.3 ICP-MS or ICP-AES may also be appropriate but at a higher instrument cost. See Test Methods D5673 and D1976.1.4 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values statedgivenin each system are mathematical conv
7、ersions and may not be exact equivalents; therefore, each system shall be used independentlyof the other.parentheses are mathematical conversion to inch-pound units that are provided for information only and are notconsidered standard.1.5 This standard does not purport to address all of the safety c
8、oncerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.1.6 This international standard was developed in accordance with internationally r
9、ecognized principles on standardizationestablished in the Decision on Principles for the Development of International Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:3D858 Test Methods f
10、or Manganese in Water1 These test methods are under the jurisdiction of ASTM Committee D19 on Water and are the direct responsibility of Subcommittee D19.05 on Inorganic Constituentsin Water.Current edition approved Sept. 1, 2012June 1, 2017. Published September 2012June 2017. Originally approved in
11、 1977. Last previous edition approved in 20072012 asD3557 02 (2007)D35571. 12. DOI: 10.1520/D3557-12.10.1520/D3557-17.2 Platte, J. A., and Marcy, V. M., “A New Tool for the Water Chemist,” Industrial Water Engineering, May 1965.3 For referencedASTM standards, visit theASTM website, www.astm.org, or
12、contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have
13、 been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official docu
14、ment.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1D1066 Practice for Sampling SteamD1068 Test Methods for Iron in WaterD1129 Terminology Relating to WaterD1193 Specif
15、ication for Reagent WaterD1687 Test Methods for Chromium in WaterD1688 Test Methods for Copper in WaterD1691 Test Methods for Zinc in WaterD1886 Test Methods for Nickel in WaterD1976 Test Method for Elements in Water by Inductively-Coupled Argon Plasma Atomic Emission SpectroscopyD2777 Practice for
16、Determination of Precision and Bias of Applicable Test Methods of Committee D19 on WaterD3370 Practices for Sampling Water from Closed ConduitsD3558 Test Methods for Cobalt in WaterD3559 Test Methods for Lead in WaterD3919 Practice for Measuring Trace Elements in Water by Graphite Furnace Atomic Abs
17、orption SpectrophotometryD4841 Practice for Estimation of Holding Time for Water Samples Containing Organic and Inorganic ConstituentsD5673 Test Method for Elements in Water by Inductively Coupled PlasmaMass SpectrometryD5810 Guide for Spiking into Aqueous SamplesD5847 Practice for Writing Quality C
18、ontrol Specifications for Standard Test Methods for Water Analysis3. Terminology3.1 DefinitionsDefinitions: For definitions of terms used in these test methods, refer to Terminology D1129.3.1.1 For definitions of terms used in this standard, refer to Terminology D1129.3.2 Definitions of Terms Specif
19、ic to This Standard:3.2.1 continuing calibration blank, na solution containing no analytes (of interest) which is used to verify blank response andfreedom from carryover.3.2.2 continuing calibration verification, na solution (or set of solutions) of known concentration used to verify freedom fromexc
20、essive instrumental drift; the concentration is to cover the range of calibration curve.3.2.3 SCE, nsaturated calomel electrode.3.2.4 spiking solution, nthe standard solution added to the polarographic cell that is used to quantitate the sample.3.2.5 stripping peak potential, nthe applied potential
21、versus SCE at which the stripping peak current is a maximum.3.2.3 SCE, nsaturated calomel electrode.3.2.6 stripping peak signal, nthe current measured at the stripping peak maximum for a metal.3.2.7 total recoverable metal, na descriptive term relating to the metal forms of cadmium recovered in the
22、acid-digestionprocedure specified in these test standards.4. Significance and Use4.1 The test for cadmium is necessary because it is a toxicant and because there is a limit specified for cadmium in potable waterin the National Interim Primary Drinking Water Regulations. This test serves to determine
23、 whether the cadmium content of potablewater is above or below the acceptable limit.5. Purity of Reagents5.1 Reagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that all reagents shall conformto the specifications of the Committee on Analytical Reagents of
24、the American Chemical Society.4 Other grades may be used,provided it is first ascertained that the reagent is of sufficiently high purity to permit its use without lessening the accuracy of thedetermination.5.2 Unless otherwise indicated, references to water shall be understood to mean reagent water
25、 conforming to SpecificationD1193, Type I. Other reagent water types may be used, provided it is first ascertained that the water is of sufficiently high purityto permit its use without adversely affecting the bias and precision of the test method. Type II water was specified at the time ofround-rob
26、in testing of this test method.6. Sampling6.1 Collect the samples in accordance with the applicable ASTM standard as follows: Practices D3370 and D1066.4 Reagent Chemicals, American Chemical Society Specifications, American Chemical Society, Washington, DC. For Suggestions on the testing of reagents
27、 not listed bythe American Chemical Society, see Annual Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia and NationalFormulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, MD.D3557 1726.2 Samples shall be preserved with HNO3 (sp gr 1.42
28、) to a pH of 2 or less immediately at the time of collection, normally about2 mL/L of HNO3. If only dissolved cadmium is to be determined, the sample shall be filtered through a 0.45-m (No. 325)membrane filter before acidification. The holding time for samples may be calculated in accordance with Pr
29、actice D4841.NOTE 1Alternatively, the pH may be adjusted in the laboratory if the sample is returned within 14 days. within 14 days of collection. However, acidmust be added at least 24 hours before analysis to dissolve any metals that adsorb to the container walls. This could reduce hazards of work
30、ing with acidsin the field when appropriate.TEST METHOD AATOMIC ABSORPTION, DIRECT7. Scope7.1 This test method covers the determination of dissolved and total recoverable cadmium in most waters and wastewaters.7.2 This test method is applicable in the range from 0.05 to 2.0 mg/Lof cadmium. The range
31、 may be extended to concentrationsgreater than 2.0 mg/L by dilution of the sample.7.3 This test method has been used successfully with reagent grade water, river water, wastewater, ground water, tap water, lakewater, and refinery effluent. The information on precision and bias may not apply to other
32、 water. It is the users responsibility toensure the validity of this test method for waters of other matrices.7. Scope7.1 This test method covers the determination of dissolved and total recoverable cadmium in most waters and wastewaters.7.2 This test method is applicable in the range from 0.05 to 2
33、.0 mg/Lof cadmium. The range may be extended to concentrationsgreater than 2.0 mg/L by dilution of the sample.7.3 This test method has been used successfully with reagent grade water, river water, wastewater, ground water, tap water, lakewater, and refinery effluent. The information on precision and
34、 bias may not apply to other water. It is the users responsibility toensure the validity of this test method for waters of other matrices.8. Summary of Test Method8.1 Cadmium is determined by atomic absorption spectrophotometry. Dissolved cadmium is determined by aspirating a portionof the filtered
35、sample directly with no pretreatment. Total recoverable cadmium is determined by aspirating the sample followinghydrochloric-nitric acid digestion and filtration. The same digestion procedure may be used to determine total recoverable nickel(Test Methods D1886), chromium (Test Methods D1687), cobalt
36、 (Test Methods D3558), copper (Test Methods D1688), iron (TestMethods D1068), lead (Test Methods D3559), manganese (Test Methods D858), and zinc (Test Methods D1691).9. Interferences9.1 Calcium concentrations above 1000 mg/L suppress the cadmium absorption. At 2000 mg/L of calcium the suppression is
37、19 %.9.2 Sodium, potassium, sulfate, and chloride (9000 mg/Leach), magnesium (4500 mg/L), iron (4000 mg/L), nitrate (100 mg/L),and nickel, lead, copper, zinc, cobalt, and chromium (10 mg/L each), do not interfere.9.3 Background correction or a chelation-extraction procedure (see Test Method B) may b
38、e necessary to determine low levelsof cadmium in some waters.NOTE 2Instrument manufacturers instructions for use of the specific correction technique should be followed.10. Apparatus10.1 Atomic Absorption Spectrophotometer, for use at 228.8 nm.NOTE 3The manufacturers instructions shall be followed f
39、or all instrumental parameters. A wavelength other than 228.8 nm may be used if it hasbeen determined to be equally suitable.10.2 Cadmium Light SourceEither cadmium hollow-cathode lamps or multielement hollow-cathode lamps, or electrodeless-discharge lamps.10.3 Pressure-Reducing ValvesThe supplies o
40、f fuel and oxidant shall be maintained at pressures somewhat higher than thecontrolled operating pressure of the instrument by suitable valves.11. Reagents and Materials11.1 Cadmium Solution, Stock (1 mL = 1.0 mg Cd)Dissolve 1.000 g of cadmium metal in a minimum quantity of HNO3 (spgr 1.42) and dilu
41、te to 1 L. A purchased cadmium stock solution of appropriate known purity is also acceptable.11.2 Cadmium Solution, Standard (1 mL = 0.1 mg Cd)Dilute 100.0 mL of the cadmium stock solution and 1 mL of HNO3(sp gr 1.42) to 1000 mL with water.D3557 17311.3 Hydrochloric Acid (sp gr 1.19)Concentrated hyd
42、rochloric acid (HCl).NOTE 4If the reagent blank concentration is greater than the method detection limit, distill the HCl or use spectrograde acid. (WarningWhen HClis distilled, an azeotropic mixture is obtained (approximately 6 N HCl.) Therefore, whenever concentrated HCl is specified for the prepa
43、ration of a reagentor in the procedure, use double the volume specified if distilled acid is used.)(WarningWhen HCl is distilled, an azeotropic mixture is obtained (approximately 6 N HCl). Therefore, wheneverconcentrated HCl is specified for the preparation of a reagent or in the procedure, use doub
44、le the volume specified if distilled acidis used.)11.4 Nitric Acid (sp gr 1.42)Concentrated nitric acid (HNO3).NOTE 5If the reagent blank concentration is greater than the method detection limit, distill the HNO3 or use a spectrograde acid.11.5 Nitric Acid (1 + 499)Add 1 volume of HNO3 (sp gr 1.42)
45、to 499 volumes of water.11.6 Oxidant:11.6.1 Air, which has been passed through a suitable filter to remove oil, water, and other foreign substances is the usual oxidant.11.7 Fuel:11.7.1 AcetyleneStandard, commercially available acetylene is the usual fuel.Acetone, always present in acetylene cylinde
46、rs,can affect analytical results.The cylinder should be replaced at 345 kPa (50 psi). (Warning“Purified” grade acetylene containinga special proprietary solvent rather than acetone should not be used with poly(vinyl chloride) tubing as weakening of the tubingwalls can cause a potentially hazardous s
47、ituation.)11.8 Paper FilterPurchase suitable filter paper. Typically the filter papers have a pore size of 0.45-m membrane. Materialsuch as fine-textured, acid-washed, ashless paper, or glass fiber paper are acceptable. The user must first ascertain that the filterpaper is of sufficient purity to us
48、e without adversely affecting the bias and precision of the test method.12. Standardization12.1 Prepare 100 mL each of a blank and at least four standard solutions to bracket the expected cadmium concentration rangeof the samples to be analyzed by diluting the standard cadmium solution (11.2) with H
49、NO3 (1 + 499). Prepare the standards eachtime the test is to be performed.performed or as determined by Practice D4841.12.2 When determining total recoverable cadmium, add 0.5 mL of HNO3 (sp gr 1.42) to each blank and standard solution andproceed as directed in 13.213.3 through 13.413.5. After the digestion of the blank and standard solutions has been completed in13.413.5, return to 12.3 to complete the standardization for total recoverable determinations. When determining dissolvedcadmium, proceed with 12.3.12.3 Aspirate the b
