1、Designation: E536 15E536 16Standard Test Methods forChemical Analysis of Zinc and Zinc Alloys1This standard is issued under the fixed designation E536; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A nu
2、mber in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S. Department of Defense.1. Scope1.1 These test methods cover the chemical analysis of z
3、inc and zinc alloys having chemical compositions within the limits ofTable 1.TABLE 1 Scope of Mass FractionRanges for Zinc and Zinc AlloysElement ConcentrationRange, %Element CompositionRange, %Aluminum 0.005 to 4.5Cadmium 0.001 to 0.5Copper 0.001 to 1.3Iron 0.001 to 0.1Lead 0.001 to 1.6Magnesium 0.
4、001 to 0.1Tin 0.001 to 0.11.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.3 These test methods appear as follows:SectionsAluminum by the EDTA Titrimetric Method (0.5 to 4.5 %) 10 17Aluminum, Cadmium, Copper, Iron, Lead,
5、and Magnesiumby the Atomic Absorption Method18 281.4 This standard does not purport to address all of the safety concerns, 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 reg
6、ulatorylimitations prior to use. Specific precautionary statements are given in Section 6.2. Referenced Documents2.1 ASTM Standards:2D1193 Specification for Reagent WaterE29 Practice for Using Significant Digits in Test Data to Determine Conformance with SpecificationsE50 Practices forApparatus, Rea
7、gents, and Safety Considerations for ChemicalAnalysis of Metals, Ores, and Related MaterialsE60 Practice for Analysis of Metals, Ores, and Related Materials by SpectrophotometryE55 Practice for Sampling Wrought Nonferrous Metals and Alloys for Determination of Chemical CompositionE88 Practice for Sa
8、mpling Nonferrous Metals and Alloys in Cast Form for Determination of Chemical CompositionE135 Terminology Relating to Analytical Chemistry for Metals, Ores, and Related MaterialsE173 Practice for Conducting Interlaboratory Studies of Methods for Chemical Analysis of Metals (Withdrawn 1998)3E1601 Pr
9、actice for Conducting an Interlaboratory Study to Evaluate the Performance of an Analytical Method1 These test methods are under the jurisdiction ofASTM Committee E01 on Analytical Chemistry for Metals, Ores, and Related Materials and are the direct responsibilityof Subcommittee E01.05 on Cu, Pb, Zn
10、, Cd, Sn, Be, Precious Metals, their Alloys, and Related Metals.Current edition approved June 1, 2015Feb. 1, 2016. Published August 2015March 2016. Originally approved in 1975. Last previous edition approved in 20082015 asE536 08.E536 15. DOI: 10.1520/E0536-15.10.1520/E0536-16.2 For referencedASTM s
11、tandards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3 The last approved version of this historical standard is referenced on www.astm.o
12、rg.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 been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior
13、editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13. Terminology3.1 For definitions of terms us
14、ed in this test method, refer to Terminology E135.4. Significance and Use4.1 These test methods for the chemical analysis of zinc metals and alloys are primarily intended as referee methods to test suchmaterials for compliance with compositional specifications. It is assumed that all who use these t
15、est methods will be trainedanalysts capable of performing common laboratory procedures skillfully and safely. It is expected that work will be performed ina properly equipped laboratory.5. Apparatus and Reagents5.1 Apparatus and reagents required for each determination are listed in separate section
16、s of each test method. The apparatus,standard solutions, and reagents shall conform to the requirements prescribed in Practices E50. Spectrometers shall conform to therequirements prescribed in Practice E60.6. Safety Hazards6.1 For precautions to be observed in the use of certain reagents in these t
17、est methods, refer to Practices E50.7. Sampling7.1 For procedures for sampling the material, refer to Practices E55 and E88.8. Rounding Calculated Values8.1 Calculated values shall be rounded to the desired number of places as directed in Practice E29, Rounding Method.9. Interlaboratory Studies9.1 T
18、hese test methods have been evaluated in accordance with Practice E173, unless otherwise noted in the precision section.ALUMINUM BY THE EDTA TITRIMETRIC METHOD10. Scope10.1 This test method covers the determination of aluminum in concentrationscompositions from 0.5 % to 4.5 %.11. Summary of Test Met
19、hod11.1 After dissolution of the sample in HCl, the solution is buffered and disodium (ethylenedinitrilo) tetraacetate (EDTA) isadded. The excess EDTA is titrated with standard zinc solution. Sodium fluoride is added to decompose the aluminum-EDTAcomplex, and the released EDTA is titrated with stand
20、ard zinc solution.12. Interferences12.1 The elements ordinarily present do not interfere if their concentrationscompositions are under the maximum limits shownin 1.1.13. Apparatus13.1 Magnetic Stirrer, with stirring bar covered with tetrafluoroethylene polymer (TFE-fluorocarbon).14. Reagents14.1 Bro
21、mcresol Green Indicator Solution (0.4 g/L)Dissolve 0.04 g of bromcresol green in 6 mL of 0.01 N sodium hydroxide(NaOH) solution and dilute to 100 mL.14.2 EDTA Solution (90 g/L)Dissolve 90.0 g of disodium (ethylenedinitrilo) tetraacetate dihydrate in about 800 mL of warmwater. Cool and dilute to 1 L.
22、NOTE 1Although it is not critical that this solution be prepared with a 1 L volumetric, doing so makes it more consistent and easier for the analystrun to run.14.3 Methyl Red Indicator Solution (0.4 g/L)Dissolve 0.1 g of methyl red in 3.72 mL of 0.1 N NaOH solution and dilute to250 mL with water. Fi
23、lter if necessary.14.4 Sodium Acetate Buffer Solution (320 g/L)Dissolve 320 g of sodium acetate trihydrate in about 800 mLof water and filter.Using a pH meter, adjust the pH of the solution to 5.5 6 0.1 with NaOH solution or acetic acid and dilute to 1 L.NOTE 2The analyst is not restricted to using
24、the 0.1 N solution of NaOH14.5 Sodium Fluoride Solution (Saturated)Dissolve 60 g of sodium fluoride (NaF) in 1 L of boiling water. Cool and filterthrough a coarse paper. Store in a polyethylene bottle.E536 16214.6 Xylenol Orange Indicator Solution (10 g/L)Dissolve 0.250 g of xylenol orange in 25 mL
25、of water. Do not use a solutionthat has stood more than 1 month.14.7 Zinc Standard Solution (1 mL = 1.00 mg Al)Dissolve 2.423 g of zinc metal (purity: 99.99 % minimum) in 20 mL ofhydrochloric acid (HCl). HCl. Dilute to 100 mL. Add 3 drops of methyl red solution and neutralize with ammonium hydroxide
26、(NHNH4OH).OH. Add HCl until the color changes to red. Transfer to a 1-L volumetric flask, dilute to volume, and mix.14.8 Purity of WaterUnless otherwise indicated, reference to water shall be understood to mean reagent water as defined byType II of Specification D1193.15. Procedure15.1 Select and we
27、igh a sample to the nearest 1 mg, in accordance with Table 2.Transfer the sample to a 400-mL beaker, and cover.15.2 Add 100 mL of HCl (1 + 1). Heat until dissolution is complete and boil for 2 minutes to 3 minutes. If a residue remains,add 1 mLof hydrogen peroxide (HH2O2) and boil the solution for a
28、t least 5 minutes to destroy excess H2O2 and expel free chlorine.NOTE 3Excess peroxide and free chlorine mustshall be removed to prevent fading of the indicators.15.3 Transfer the solution to a 200-mL volumetric flask, dilute to volume, and mix.15.4 Using a pipet, transfer the aliquot specified in 1
29、5.1 to a 500-mL wide-mouth Erlenmeyer flask.15.5 Add the volume of EDTA solution specified in 15.1 and dilute to 200 mL.NOTE 4The amount of EDTA added mustshall be sufficient to complex the zinc and aluminum with some excess. The amount of EDTA required is5.7 mg for each milligram of zinc and 14.0 m
30、g for each milligram of aluminum.15.6 Add five drops or six drops of methyl red solution. Add NH4OH until the color changes to orange.15.7 Add 25 mL of sodium acetate buffer solution and boil for 3 minutes to 5 minutes. Cool in a water bath.15.8 Add four drops of xylenol orange solution and five dro
31、ps or six drops of bromcresol green solution.15.9 Using a TFE-fluorocarbon-covered stirring bar and a magnetic stirrer, stir the solution while adding standard zinc solutionfrom a 50-mL buret to complex the excess EDTA.Add the solution dropwise as the end point is approached. Continue the titrationu
32、ntil the color changes from green to red. Refill the buret.15.10 Add 25 mL of NaF solution and boil for 3 minutes to 5 minutes. Cool in a water bath.15.11 Titrate with standard zinc solution as directed in 15.9 and record the volume to the nearest 0.01 mL.16. Calculation16.1 Calculate the percentage
33、 of aluminum as follows:Aluminum,%5AB/C!3100 (1)where:A = standard zinc solution used in 15.11, mL;B = aluminum equivalent of the standard zinc solution, g/mL (noted in 14.7); andC = sample represented in the aliquot taken in 15.1, g.17. Precision and Bias17.1 PrecisionEight laboratories cooperated
34、in testing this test method and obtained the results summarized in Table 3.17.2 BiasNo information concerning the accuracy of this test method is available because certified reference materials suitablefor chemical test methods were not available when the interlaboratory test was performed. The anal
35、yst is urged to use an acceptedreference material, if available, to determine that the accuracy of results is satisfactory.17.3 Practice E173 has been replaced by Practice E1601.The reproducibility Index R2, corresponds to the Reproducibility IndexR of Practice E1601. Likewise the Repeatability Inde
36、x R1 of Practice E173 corresponds to the Repeatability Index r of PracticeE1601.TABLE 2 Recommended Sample WeightAluminum, % SampleWeight, g Aliquot, mL EDTAAddition, mL0.5 to 1.5 10.0 50 165 to 1681.5 to 2.5 6.0 50 103 to 1062.5 to 4.5 5.0 40 72 to 75E536 163ALUMINUM, CADMIUM, COPPER, IRON, LEAD, A
37、ND MAGNESIUM BY THE ATOMIC ABSORPTIONMETHOD18. Scope18.1 This test method covers the determination of aluminum in concentrationscompositions from 0.002 % to 0.5 %, cadmiumfrom 0.001 % to 0.5 %, copper from 0.001 % to 1.3 %, iron from 0.003 % to 0.1 %, lead from 0.002 % to 1.6 %, and magnesiumfrom 0.
38、001 % to 0.1 %.19. Summary of Test Method19.1 An HCl solution of the sample is aspirated into the flame of an atomic absorption spectrometer. The absorption of theresonance line energy from the spectrum of each element is measured and compared with that of calibration solutions of the sameelement. T
39、he wavelengths of the spectral lines and other method parameters are tabulated in 22.1 for each element.20. Calibration Composition Range20.1 The calibration composition range for each element mustshall be determined experimentally, because the optimum rangewill depend upon the individual instrument
40、. If the optimum calibrationcomposition range and instrument parameters have beendetermined, proceed in accordance with Section 26; otherwise, determine the calibrationcomposition range in accordance withSection 22.NOTE 5The composition range will depend on the instrument. Section 24.1 lists the typ
41、ical calibration composition ranges that most often will beacceptable, however this can be determined by using the criteria in Section 22. The analyst may find that different calibration composition ranges arerequired and must adjust be adjusted accordingly to suit their instrument.21. Interferences
42、21.1 The elements ordinarily present do not interfere if their concentrationscompositions are under the maximum limits shownin 1.1.22. Apparatus22.1 Atomic Absorption Spectrometer, equipped with a premix burner, with facilities for using the oxidizer-fuel combinationslisted in Table 4. Use hollow-ca
43、thode lamps operated in accordance with manufacturers recommendations as sources for thespectral lines. The instrument may be considered suitable for this test method if a composition range can be found for which theminimum response, calibration variability, and reference variability tabulated in Ta
44、ble 4 can be met.22.1.1 Prepare the dilute standard solution, reference, and calibration solutions in accordance with Section 24. Refer to Table5 for suggested initial positions.TABLE 3 Statistical InformationTestSpecimenAluminumFound, %Repeatability(R1, E173)Reproducibility(R2, E173)G-3 0.3998 0.01
45、90 0.0254H-2 4.04 0.052 0.074TABLE 4 Minimum Response, Calibration, and ReferenceVariabilityElement SpectralLine, nm Oxidizer-Fuel StandardSolutionMinimumResponse,UnitsCalibra-tion Vari-ability, %ReferenceVariabil-ity, %Aluminum 309.2 N2OC2H2“A”“B”9253.51.02.00.5Cadmium 228.8 AirC2H2. 50 0.8 0.4Copp
46、er 324.7 AirC2H2“A”“B”15502.00.80.80.4Iron 248.3 AirC2H2“A”“B”15252.01.01.00.5Lead 217.0 AirC2H2“A”“B”10302.01.01.50.4Magnesium 285.2 N2OC2H2. 20 1.5 0.8E536 16422.1.2 Prepare the instrument for use in accordance with in 26.1. Measure the instrument response while aspirating the referencesolution, t
47、he lowest, and the two highest calibration solutions, performing the measurements in accordance with 26.2.2 and 26.2.3.22.1.3 Minimum ResponseCalculate the difference between the readings of the two highest of the five equally spacedcalibration solutions. This difference mustshall be equal to or gre
48、ater than the number of scale units specified in Table 4. Forpurposes of this test method, the scale unit is defined as one in the least significant digit of the scale reading of the mostconcentrated calibration solution.22.1.4 Curve LinearityCalculate the difference between the scale readings of th
49、e reference solution and the lowest of the fiveequally spaced calibration solutions. If necessary, convert this difference and the difference calculated in 22.1.3 to absorbance units.Divide the difference for the highest interval by that for the lowest interval. This ratio mustshall be equal to or greater than 0.70.22.1.5 If the instrument meets or surpasses the minimum response and curve linearity criteria, the initial concentrationcom-position range may be considered suitable. In this case, proceed in accordance with 22.1.7; o
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