ASTM E396-2005(2011) 8750 Standard Test Methods for Chemical Analysis of Cadmium《镉的化学分析标准试验方法》.pdf

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1、Designation: E396 05 (Reapproved 2011)Standard Test Methods forChemical Analysis of Cadmium1This standard is issued under the fixed designation E396; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A numb

2、er in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 These test methods cover the chemical analysis ofcadmium having chemical compositions with the followinglimits:Element Concentration, max,

3、%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 the Molybdenum Blue Photometric Method0.001 to 0.005%40-50Copper by

4、 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 Method 0.001 to 0.05% 20-29Thallium by the Rhodamine B Photometric

5、Method0.0003 to 0.005%30-39Tin by the 8-Quinolinol Photometric Method 0.0025 to 0.0150% 73-821.3 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.4 This standard does not purport to address all of thesafety concerns, if any, as

6、sociated 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 information is given in Section 6 and 25.8.2. Referenced Documents2.1 AST

7、M Standards:2B440 Specification for CadmiumD1193 Specification 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 Materi

8、alsE55 Practice for Sampling Wrought Nonferrous Metals andAlloys for Determination of Chemical CompositionE60 Practice for Analysis of Metals, Ores, and RelatedMaterials by Molecular Absorption SpectrometryE88 Practice for Sampling Nonferrous Metals and Alloys inCast Form for Determination of Chemic

9、al CompositionE135 Terminology Relating to Analytical Chemistry forMetals, Ores, and Related MaterialsE173 Practice for Conducting Interlaboratory Studies ofMethods for Chemical Analysis of Metals3E1601 Practice for Conducting an Interlaboratory Study toEvaluate the Performance of an Analytical Meth

10、od3. Terminology3.1 For definitions of terms used in this test method, refer toTerminology E135.4. 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 B440.It

11、is assumed that all who use these test methods will be trainedanalysts capable of performing common laboratory proceduresskillfully and safely. It is expected that work will be performedin a properly equipped laboratory.1These test methods are under the jurisdiction of ASTM Committee E01 onAnalytica

12、l 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 May 15, 2011. Published May 2011. Originallyapproved in 1970. Last previous edition approved in 2005 as E396

13、 05. DOI:10.1520/E0396-05R11.2For 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 page onthe ASTM website.3Withdrawn. The last approved ve

14、rsion of this historical standard is referencedon www.astm.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5. Apparatus, Reagents, and Photometric Practice5.1 Apparatus and reagents required for each determinationare listed in se

15、parate sections 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

16、E60.6. 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 products shall be sampled in accordance withPractice E55. Cast products shall be sampled in accordancewith Practice E88. However, these test meth

17、ods do not super-sede any sampling requirements specified in a specific ASTMmaterial specification.8. Rounding Calculated Values8.1 Calculated values shall be rounded to the desired num-ber of places as directed in Practice E29.9. Interlaboratory Studies9.1 These test methods have been evaluated in

18、accordancewith Practices E173, unless otherwise noted in the precisionsection.COPPER BY THE NEOCUPROINE PHOTOMETRICMETHOD10. Scope10.1 This test method covers the determination of copper inconcentrations from 0.002 to 0.030 %.11. Summary of Test Method11.1 Copper is separated as cuprous copper from

19、othermetals by extraction of the copper-neocuproine complex withchloroform. Photometric measurement is made at approxi-mately 455 nm.12. Concentration Range12.1 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 ha

20、s 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 and reagents used.13. Stability of Color13.1 The color develops within 5 min and the extractedcomplex is stable. However, because of the vola

21、tile nature ofthe solvent, it is advisable to take photometric readingspromptly.14. Interferences14.1 The elements ordinarily present do not interfere if theirconcentrations are under the maximum limits shown in 1.1.15. Reagents15.1 Chloroform (CHCl3).15.2 Copper, Standard Solution (1 mL = 0.01 mg C

22、u)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 of 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 ofHN

23、O3(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 water. Prepare fresh as needed.15.4 Metacresol Purple Indicator Solution (1 g/L)Dissolve 0.100 g of metacresol purple together with 1 pellet of

24、sodium 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-dimethyl-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

25、 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 water as definedby Type II of Specification D1193.16. Preparation of Calibration Curve16.1 Calibration Solution:16.1.1 Using pipets, transfer 2, 5

26、, 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 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 m

27、L 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 citrate 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 sta

28、nd 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 Transfer 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

29、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 PhotometerMeasure the cell correc-tion using absorption cells with a 1-cm light path and a lightband centered at approximately 455 nm (Note 3). Usin

30、g the testcell, take the photometric readings of the calibration solutions.NOTE 3Avoid transfer of water to the absorption cell in the followingmanner. Insert a loose plug of sterilized absorbent cotton into the stem ofeach separatory funnel. Just prior to filling the absorption cell with thesolutio

31、n in the separatory funnel, discard about 1 mL of the CHCl3layerthrough the cotton plug and immediately transfer a suitable portion of theCHCl3layer into the dry absorption cell.E396 05 (2011)216.4.2 Single-Cell PhotometerTransfer a suitable portionof the reference solution to an absorption cell wit

32、h 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 photometric readings ofthe calibration solutions.16.5 Calibration CurvePlot the net photometric readingsof the calibration solu

33、tions 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 mL of HNO3(1 + 1).When dissolution is complete, add 20 mL of water and boilgently to eliminate oxides of nitrogen. Cool, dilute to abo

34、ut 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 using the same amount of all reagents with thesample omitted, for use as the reference solution.17.3 Color DevelopmentProceed as direc

35、ted 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 of 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 f

36、inal test solution, mg,andB = sample represented in 25 mL of final test solution, g.19. Precision and Bias19.1 PrecisionEight laboratories cooperated in testingthis test method and obtained the data summarized in Table 1.19.2 AccuracyNo certified reference materials suitablefor testing this test met

37、hod were available when the interlabo-ratory testing program was conducted. The user of this testmethod is encouraged to employ accepted reference materials,if available, to determine the accuracy of this test method asapplied in a specific laboratory.19.3 E173 has been replaced by Practice E1601. T

38、he repro-ducibility Index R2corresponds to the Reproducibility Index Rof Practice E1601. Likewise the Repeatability Index R1corre-sponds to the Repeatability Index r of Practice E1601.LEAD BY THE DITHIZONE PHOTOMETRICMETHOD20. Scope20.1 This test method covers the determination of lead inconcentrati

39、ons 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 dithizonein the chloroform is then removed by extraction with anammoniacal sulfite solution. Photometric measurement is madeat approximatel

40、y 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. Stability of Color23.1 The color is stable for at least2hifprotected fromdirect sunlight; however, because of the volatile nature of the

41、solvent, it is advisable to take photometric readings promptly.24. Interferences24.1 The elements ordinarily present in cadmium do notinterfere if their concentrations are under the maximum limitsshown in 1.1.25. Reagents25.1 Ascorbic Acid.25.2 Bromine Water (Saturated).25.3 Chloroform (CHCl3).25.4

42、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 several hours. Store in a cool, dark place. Just before use,dilute 50 mL of this solution to 500 mL with CHCl3in a dryborosilicate bot

43、tle 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 eliminate 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

44、 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 Potassium Cyanide Solution (200 g/L)Dissolve 200g of potassium cyanide (KCN) (low in lead and sulfide)(Warning See 25.8) in water, and dilute

45、 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 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

46、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 inhalation of fumes andexposure of the skin to the chemical and its solutions. Do notallow solutions containing cyanide to come in con

47、tact 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 tartrate dihydrate in water, and dilute to 200 mL.25.10 Thioglycolic Acid Solution (1 + 99)Dilute 1.0 mLof thioglycolic acid (mercapto

48、acetic 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 acid that has stood for more than 1 week.E396 05 (2011)325.11 Purity of WaterUnless otherwise indicated, refer-ence to water shall be u

49、nderstood to mean reagent water asdefined by Type II of Specification D1193.26. 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 NH4