ASTM E396-2005 Standard Test Methods for Chemical Analysis of Cadmium《镉化学分析的标准试验方法》.pdf

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1、Designation: E 396 05Standard Test Methods forChemical Analysis of Cadmium1This standard is issued under the fixed designation E 396; 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 parenthese

2、s indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.NoteCorrections were made throughout and the year date changed on July 25, 2005.1. Scope1.1 These test methods cover the chemical analysis ofcadmium having chemical c

3、ompositions with the followinglimits:Element Concentration, max, %Antimony 0.001Arsenic 0.003Copper 0.015Lead 0.025Silver 0.010Thallium 0.003Tin 0.010Zinc 0.0351.2 The test methods appear in the following order:SectionsAntimony by the Rhodamine B Photometric Method0.0002 to 0.0010%62-72Arsenic by th

4、e Molybdenum Blue Photometric Method0.001 to 0.005%40-50Copper by the Neocuproine Photometric Method 0.002 to 0.030% 10-19Copper, Lead, Silver, and Zinc by the Atomic Absorption Method0.004 to 0.02% Cu, 0.01 to 0.05% Pb, 0.004 to 0.02 % Agand 0.01 to 0.05% Zn51-61Lead by the Dithizone Photometric Me

5、thod 0.001 to 0.05% 20-29Thallium by the Rhodamine B Photometric Method0.0003 to 0.005%30-39Tin by the 8-Quinolinol Photometric Method 0.0025 to 0.0150% 73-821.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user

6、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 information is given in Section 6 and 25.8.2. Referenced Documents2.1 ASTM Standards:2B 440 Specification for CadmiumD 1193 Specific

7、ation for Reagent WaterE29 Practice for Using Significant Digits in Test Data toDetermine Conformance with SpecificationsE50 Practices for Apparatus, Reagents, and Safety Consid-erations for Chemical Analysis of Metals, Ores, andRelated MaterialsE55 Practice for Sampling Wrought Nonferrous Metals an

8、dAlloys for Determination of Chemical CompositionE60 Practice for Analysis of Metals, Ores, and RelatedMaterials by Molecular Absorption SpectrometryE88 Practice for Sampling Nonferrous Metals and Alloysin Cast Form for Determination of Chemical CompositionE 135 Terminology Relating to Analytical Ch

9、emistry forMetals, Ores, and Related MaterialsE 173 Practices for Conducting Interlaboratory Studies ofMethods for Chemical Analysis of Metals3E 1601 Practice for Conducting an Interlaboratory Study toEvaluate the Performance of an Analytical Method3. Terminology3.1 For definitions of terms used in

10、this test method, refer toTerminology E 135.4. Significance and Use4.1 These test methods for the chemical analysis of cad-mium are primarily intended to test such material for compli-ance with compositional specifications in Specification B 440.It is assumed that all who use these test methods will

11、 be trainedanalysts capable of performing common laboratory proceduresskillfully and safely. It is expected that work will be performedin a properly equipped laboratory.5. Apparatus, Reagents, and Photometric Practice5.1 Apparatus and reagents required for each determinationare listed in separate se

12、ctions preceding the procedure. Theapparatus, standard solutions, and reagents shall conform to therequirements prescribed in Practices E50. Photometers shallconform to the requirements prescribed in Practice E60.5.2 Photometric practice prescribed in these methods shallconform to Practice E60.1Thes

13、e test methods are under the jurisdiction of ASTM Committee E01 onAnalytical Chemistry for Metals, Ores, and Related Materials and are the directresponsibility of Subcommittee E01.05 on Cu, Pb, Zn, Cd, Sn, Be, their Alloys andRelated Metals.Current edition approved July 25, 2005. Published July 2005

14、. Originallyapproved in 1970. Last previous edition approved in 2004 as E 396 04a.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary pag

15、e onthe ASTM website.3Withdrawn.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6. Safety Hazards6.1 For precautions to be observed in the use of certainreagents in these test methods, refer to Practices E50.7. Sampling7.1 Wrought pr

16、oducts shall be sampled in accordance withPractice E55. Cast products shall be sampled in accordancewith Practice E88. However, these test methods do notsupersede any sampling requirements specified in a specificASTM material specification.8. Rounding Calculated Values8.1 Calculated values shall be

17、rounded to the desired num-ber of places as directed in Practice E29.9. Interlaboratory Studies9.1 These test methods have been evaluated in accordancewith Practices E 173, unless otherwise noted in the precisionsection.COPPER BY THE NEOCUPROINE PHOTOMETRICMETHOD10. Scope10.1 This test method covers

18、 the determination of copper inconcentrations from 0.002 to 0.030 %.11. Summary of Test Method11.1 Copper is separated as cuprous copper from othermetals by extraction of the copper-neocuproine complex withchloroform. Photometric measurement is made at approxi-mately 455 nm.12. Concentration Range12

19、.1 The recommended concentration range is from 0.01 to0.15 mg of copper for each 25 mL of solution, using a 1-cmcell.NOTE 1This test method has been written for cells having a 1-cmlight path. Cells having other dimensions may be used, provided suitableadjustments can be made in the amounts of sample

20、 and reagents used.13. Stability of Color13.1 The color develops within 5 min and the extractedcomplex is stable. However, because of the volatile nature ofthe solvent, it is advisable to take photometric readingspromptly.14. Interferences14.1 The elements ordinarily present do not interfere if thei

21、rconcentrations are under the maximum limits shown in 1.1.15. Reagents15.1 Chloroform (CHCl3).15.2 Copper, Standard Solution (1 mL = 0.01 mg Cu)Dissolve 0.1000 g of copper (purity: 99.9 % min) in 10 mL ofHNO3(1 + 1). Add 25 mL of water, heat to boiling, and boilgently for 2 min to eliminate oxides o

22、f nitrogen. Cool, transferto a 100-mL volumetric flask, dilute to volume, and mix.Transfer 5.00 mL to a 500-mL volumetric flask. Add 1 mL ofHNO3(1 + 1), dilute to volume, and mix.15.3 Hydroxylamine Hydrochloride Solution (100 g/L)Dissolve 5.0 g of hydroxylamine hydrochloride(NH2OH HCl) in 50 mL of w

23、ater. Prepare fresh as needed.15.4 Metacresol Purple Indicator Solution (1 g/L)Dissolve 0.100 g of metacresol purple together with 1 pellet ofsodium hydroxide (NaOH) in about 10 mL of water bywarming. Dilute to 100 mL, and mix.15.5 Neocuproine Solution (1 g/L)Dissolve 0.10 g ofneocuproine (2,9-dimet

24、hyl-1,10-phenanthroline hemihydrate)in 100 mL of either methanol or 95 % ethanol.15.6 Sodium Citrate Solution (300 g/L)Dissolve 300 g ofsodium citrate dihydrate in water, dilute to 1 L, and mix.15.7 Purity of WaterUnless otherwise indicated, referenceto water shall be understood to mean reagent wate

25、r as definedby Type II of Specification D 1193.16. Preparation of Calibration Curve16.1 Calibration Solution:16.1.1 Using pipets, transfer 2, 5, 10, 15, and 20 mL ofcopper solution (1 mL = 0.01 mg Cu) to five 150-mL beakers,and dilute to about 40 mL.16.1.2 Add 2 drops of metacresol purple indicator

26、solution,and then add HNO3(1 + 1) dropwise to the red color change ofthe indicator. Proceed as directed in 16.3.16.2 Reference SolutionAdd 40 mL of water to a 150- mLbeaker. Proceed as directed in 16.1.2.16.3 Color Development:16.3.1 Add 10 mL of NH2OH HCl solution, and stir. Add10 mL of sodium citr

27、ate solution, and stir. Add NH4OH to thepurple color of the indicator (pH about 8.5). Add 5.0 mL ofneocuproine solution, stir, and allow to stand for 5 min.NOTE 2The precipitate that may form upon addition of sodium citratesolution will redissolve when the pH is raised to 8.5 with NH4OH.16.3.2 Trans

28、fer to a 125-mL separatory funnel marked at 80mL, and dilute to the mark with water. Add 25.0 mL of CHCl3.Shake vigorously for 45 s, and allow the layers to separate.Draw off and discard about 1 mL of the CHCl3layer to rinsethe stem of the separatory funnel.16.4 Photometry:16.4.1 Multiple-Cell Photo

29、meterMeasure the cell correc-tion using absorption cells with a 1-cm light path and a lightband centered at approximately 455 nm (Note 3). Using the testcell, take the photometric readings of the calibration solutions.NOTE 3Avoid transfer of water to the absorption cell in the followingmanner. Inser

30、t a loose plug of sterilized absorbent cotton into the stem ofeach separatory funnel. Just prior to filling the absorption cell with thesolution in the separatory funnel, discard about 1 mL of the CHCl3layerthrough the cotton plug and immediately transfer a suitable portion of theCHCl3layer into the

31、 dry absorption cell.16.4.2 Single-Cell PhotometerTransfer a suitable portionof the reference solution to an absorption cell with a 1-cm lightpath and adjust the photometer to the initial setting, using alight band centered at approximately 455 nm (Note 1). Whilemaintaining this adjustment, take the

32、 photometric readings ofthe calibration solutions.E39605216.5 Calibration CurvePlot the net photometric readingsof the calibration solutions against milligrams of copper per 25mL of solution.17. Procedure17.1 Test SolutionTransfer a 0.5-g sample, weighed to thenearest 1 mg, to a 150-mL beaker. Add 5

33、 mL of HNO3(1 + 1).When dissolution is complete, add 20 mL of water and boilgently to eliminate oxides of nitrogen. Cool, dilute to about 40mL, and add 2 drops of metacresol purple indicator solution.Proceed as directed in 17.3.17.2 Reference SolutionCarry a reagent blank through theentire procedure

34、 using the same amount of all reagents with thesample omitted, for use as the reference solution.17.3 Color DevelopmentProceed as directed in 16.3.17.4 PhotometryProceed as directed in 16.4.18. Calculation18.1 Convert the net photometric reading of the test solutionto milligrams of copper by means o

35、f the calibration curve.Calculate the percentage of copper as follows:Copper, % 5 A/B 3 10! (1)where:A = copper found in the 25 mL of final test solution, mg,andB = sample represented in 25 mL of final test solution, g.19. Precision and Bias19.1 PrecisionEight laboratories cooperated in testingthis

36、test method and obtained the data summarized in Table 1.19.2 AccuracyNo certified reference materials suitablefor testing this test method were available when the interlabo-ratory testing program was conducted. The user of this testmethod is encouraged to employ accepted reference materials,if avail

37、able, to determine the accuracy of this test method asapplied in a specific laboratory.19.3 E 173 has been replaced by Practice E 1601. Thereproducibility Index R2corresponds to the ReproducibilityIndex R of Practice E 1601. Likewise the Repeatability IndexR1corresponds to the Repeatability Index r

38、of Practice E 1601.LEAD BY THE DITHIZONE PHOTOMETRICMETHOD20. Scope20.1 This test method covers the determination of lead inconcentrations from 0.001 to 0.05 %.21. Summary of Test Method21.1 Lead dithizonate is extracted with chloroform from abuffered cyanide solution at a pH of 8.5. The excess dith

39、izonein the chloroform is then removed by extraction with anammoniacal sulfite solution. Photometric measurement is madeat approximately 515 nm.22. Concentration Range22.1 The recommended concentration range is from 0.005to 0.050 mg of lead for each 25 mL of solution, using a 1-cmcell (Note 1).23. S

40、tability of Color23.1 The color is stable for at least2hifprotected fromdirect sunlight; however, because of the volatile nature of thesolvent, it is advisable to take photometric readings promptly.24. Interferences24.1 The elements ordinarily present in cadmium do notinterfere if their concentratio

41、ns are under the maximum limitsshown in 1.1.25. Reagents25.1 Ascorbic Acid.25.2 Bromine Water (Saturated).25.3 Chloroform (CHCl3).25.4 Dithizone Solution (0.01 g/L of CHCl3)Dissolve0.05 g of dithizone (diphenylthiocarbazone) in a freshlyopened 700-g bottle of CHCl3. Mix several times over a periodof

42、 several hours. Store in a cool, dark place. Just before use,dilute 50 mL of this solution to 500 mL with CHCl3in a dryborosilicate bottle or flask, and mix.25.5 Lead, Standard Solution (1 mL = 0.005 mg Pb)Dissolve 0.1000 g of lead (purity: 99.9 % min) in 20 mL ofHNO3(1 + 1), and boil gently to elim

43、inate oxides of nitrogen.Cool, transfer to a 200-mL volumetric flask, dilute to volume,and mix. Transfer 5.00 mL to a 500-mL volumetric flask, diluteto volume, and mix. Prepare the final solution fresh as needed.25.6 Metacresol Purple Indicator Solution (1 g/L)Proceed as directed in 15.4.25.7 Potass

44、ium Cyanide Solution (200 g/L)Dissolve 200g of potassium cyanide (KCN) (low in lead and sulfide)(Warning See 25.8) in water, and dilute to 1 L. Bring to aboil and boil for 2 min. Cool, and store in a polyethylene bottle.25.8 Sodium Sulfite Wash SolutionDissolve1gofsodiumsulfite (Na2SO3) in about 300

45、 mL of water in a 1-L volumetricflask. Add 20 mL of the KCN solution and 475 mL of NH4OH(1 + 1) which has been prepared from a freshly opened bottle.Dilute to volume, and mix. Store in a polyethylene bottle.(WarningThe preparation, storage, and use of KCN solu-tions require care and attention. Avoid

46、 inhalation of fumes andexposure of the skin to the chemical and its solutions. Do notallow solutions containing cyanide to come in contact withstrongly acidic solutions. Work in a well-ventilated hood. Referto Section 6 of Practices E50.)25.9 Sodium Tartrate Solution (250 g/L)Dissolve 50 g ofsodium

47、 tartrate dihydrate in water, and dilute to 200 mL.25.10 Thioglycolic Acid Solution (1 + 99)Dilute 1.0 mLof thioglycolic acid (mercaptoacetic acid) to 100 mL withwater. Refrigerate both the concentrated and diluted acidsolutions. Do not use concentrated acid that is more than 1 yearold, nor diluted

48、acid that has stood for more than 1 week.TABLE 1 Statistical InformationSpecimenCopper Found,%Repeatability(R1, E 173)Reproducibility(R2, E 173)1 0.0074 0.003 0.00132 0.0173 0.0018 0.0031E39605325.11 Purity of WaterUnless otherwise indicated, refer-ence to water shall be understood to mean reagent w

49、ater asdefined by Type II of Specification D 1193.26. Preparation of Calibration Curve26.1 Calibration SolutionsUsing pipets, transfer 1, 2, 3,5, and 10-mL volumes of lead solution (1 mL = 0.005 mg Pb)to 125-mL separatory funnels (set No. 1). Dilute to 15 mL withwater and add 1 drop of metacresol purple indicator solution.26.2 Reference SolutionTransfer 15 mL of water to a125-mL separatory funnel (one of set No. 1), and add 1 drop ofmetacresol purple indicator solution.26.3 Color Development:26.3.1 Add NH4OH (1 + 1) dropwise, with sw