ASTM_E_1446_-_13.pdf

Designation:E144613Standard Test Method forChemical Analysis of Refined Gold by Direct CurrentPlasma Atomic Emission Spectrometry1This standard is issued under the fixed designation E1446;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 indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers the analysis of refined gold forthe following elements having the following chemical compo-sition limits:ElementContent Range,g/gCopper17 to 300Iron6 to 150Lead17 to 100Palladium7 to 350Silver17 to 5001.2 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.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.Referenced Documents2.1 ASTM Standards:2B562 Specification for Refined GoldE29 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 MaterialsE135 Terminology Relating to Analytical Chemistry forMetals,Ores,and Related MaterialsE173 Practice for Conducting Interlaboratory Studies ofMethods for Chemical Analysis of Metals(Withdrawn1998)3E882 Guide for Accountability and Quality Control in theChemical Analysis LaboratoryE1097 Guide for Determination of Various Elements byDirect Current Plasma Atomic Emission SpectrometryE1601 Practice for Conducting an Interlaboratory Study toEvaluate the Performance of an Analytical Method3.Terminology3.1 DefinitionsFor definitions of terms used in this testmethod,refer to Terminology E135.4.Summary of Test Method4.1 The sample is dissolved with acids.Calibration solu-tions are prepared from pure reagents to match the samplematrix.Analysis is performed with the direct-current plasmaatomic emission spectrometer.Element contents are measuredby comparing emission intensities from the sample with thoseof the calibration solutions.Copper is measured at 327.3 nm or324.7 nm;iron at 259.9 nm;lead at 405.7 nm;palladium at340.4 nm;and silver at 328.0 nm or 338.3 nm.5.Significance and Use5.1 This test method for the analysis of fine gold is primarilyintended to test such material for compliance with composi-tional specifications.It is assumed that all who use this testmethod will be trained analysts capable of performing commonlaboratory procedures skillfully and safely.It is expected thatwork will be performed in a properly equipped laboratory andoperated in accordance with Guide E882.6.Interferences6.1 Spectral line interferences and spectrochemical back-ground effects are overcome by preparing a matrix-matchedcalibration standard series to approximate the prepared sample.1This test method is under the jurisdiction of ASTM Committee E01 onAnalytical Chemistry for Metals,Ores,and Related Materials and is the directresponsibility of Subcommittee E01.05 on Cu,Pb,Zn,Cd,Sn,Be,Precious Metals,their Alloys,and Related Metals.Current edition approved Oct.1,2013.Published October 2013.Originallyapproved in 1992.Last previous edition approved in 2005 as E1446 05.DOI:10.1520/E1446-13.2For 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.3The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 6.2 The analyte wavelengths mentioned herein have beenpreviously evaluated for spectral line interferences and foundto be the optimum emission wavelengths for refined goldsample testing.Alternative wavelengths,if shown to be free ofinterferences,may also be used.7.Apparatus7.1 D-C Argon Plasma Atomic Emission SpectrometerTheinstrument must be equipped with a sample nebulizationsystem compatible with mineral acids and with test solutionscontaining 4%total solids.Follow the manufacturers instruc-tions for installation and operation.8.Reagents and Materials8.1 ArgonPurity:99.998%minimum.8.2 Copper Standard Solution(1 mL=1.0 mg Cu)Transfer 1.000 g of copper metal(purity:99.9%minimum)toa 400-mL beaker.Add 60 mL of HNO3(1+1)in 10-mLincrements and heat gently on a hot plate.When dissolution iscomplete,cool,then transfer to a 1-L volumetric flask.Diluteto volume with HNO3(1+99)and mix.This solution is stablefor at least six months.8.3 Iron Standard Solution(1 mL=1.0 mg Fe)Transfer1.000 g of iron metal(purity:99.9%minimum)to a 400-mLbeaker.Add 50 mL of