ASTM_C_1284_-_10.pdf

Designation:C128410Standard Practice forElectrodeposition of the Actinides for Alpha Spectrometry1This standard is issued under the fixed designation C1284;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 practice covers the preparation of separated ac-tinide fractions for alpha spectrometry measurement.2It isapplicable to any of the actinides that can be dissolved in diluteammonium sulfate solution.Examples of applicable actinidefractions would be the final elution from an ion exchangeseparation or the final strip from a solvent extraction separa-tion.1.2 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:3C1163 Practice for Mounting Actinides for Alpha Spectrom-etry Using Neodymium FluorideD1193 Specification for Reagent Water3.Summary of Practice3.1 Guidance is provided for the electrodeposition of sepa-rated actinide fractions onto metal discs.This practice is basedon cathodic deposition of the hydrated oxides of the actinidesfrom an acidic medium containing an ammonium salt.Theresultant electrodeposited samples are suitable for alpha spec-trometry measurements.4.Significance and Use4.1 The determination of actinide elements by alpha spec-trometry measurement is an essential part of many environ-mental research,bioassay,and monitoring programs.Alphaspectrometry measurements identify and quantify the alpha-emitting actinide elements.A variety of separation methodswill typically precede the electrodeposition of a sample foralpha spectrometry measurements.In addition to the electrode-position procedure presented in this practice,the scientificliterature contains other procedures for actinide electrodeposi-tion.NOTE1An alternate method for mounting actinides for alpha spec-trometry measurements by coprecipitation with neodymium fluoride isdescribed in Practice C1163.5.Interferences5.1 Any element present in the separated fraction which iscapable of cathodic electrodeposition will be present on themetal disc.In particular210Po(5.30 MeV)deposited on thedisc would interfere with the yield determination of232U(5.32MeV)or243Am(5.28 MeV)tracers used in the determinationof isotopic uranium and241Am(5.15 MeV),respectively.5.2 Incomplete separation of rare earth elements or incom-plete wet ashing for the removal of organic material willdecrease the efficiency of the electrodeposition and may resultin a thick deposit unsuitable for alpha spectrometry measure-ment.5.3 The quantity of actinide should be such that 5 g cm2are electrodeposited on the metal disc.Thicker deposits aretypically unsuitable for measurement by alpha spectrometrydue to the resulting attenuation and decrease in energy resolu-tion.6.Apparatus6.1 Electrodeposition Power SupplyConstant current,ad-justable from 0 to 2 A with indicating meter.6.2 Electrodeposition CellDisposable cells are recom-mended.The cells should have a minimum volume capacity of25 mL.6.3 Metal DiscsStainless steel disc,or other metal discsuch as platinum,polished to a mirror finish on one side.The1This practice is under the jurisdiction of ASTM Committee C26 on NuclearFuel Cycle and is the direct responsibility of Subcommittee C26.05 on Methods ofTest.Current edition approved June 1,2010.Published July 2010.Originally approvedin 1994.Last previous edition approved in 2005 as C1284-00(2005).DOI:10.1520/C1284-10.2Based on Talvitie,N.A.,“Electrodeposition of Actinides for Alpha Spectro-metric Determination,”Analytical Chemistry,Vol 44,1972,pp.280283.3For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 diameter of the disc is determined by diameter of the electrode-position cell.The current density should be approximately 0.5A cm2of the disc area.6.4 Electrodeposition AnodeThe exact dimensions of theanode will be determined by the cross-sectional area and depthof the electrodeposition cell.For example,a 1.5 mm diameterby 100 mm long platinum wire with loop facing the cathode(stainless steel disc).The anode loop should be just slightlysmaller than the cathode.6.5 Insulated Base,to support the cell and provide thecathode connection.7.Reagents7.1 Purity of Reagen