ASTM_C_1614_-_05_2010.pdf

Designation:C161405(Reapproved 2010)Standard Practice for theDetermination of237Np,232Th,235U and238U in Urine byInductively Coupled Plasma-Mass Spectrometry(ICP-MS)and Gamma Ray Spectrometry1This standard is issued under the fixed designation C1614;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 separation and preconcentrationof neptunium-237(237Np),thorium-232(232Th),uranium-235(235U)and uranium-238(238U)from urine followed by quan-titation using ICP-MS.1.2 This practice can be used to support routine bioassayprograms.The minimum detectable concentrations(MDC)forthis method,taking the preconcentration factor into account,are approximately 1E-2Bq for237Np(0.38ng),2E-6Bq for232Th(0.50ng),4E-5Bq for235U(0.50ng)and 6E-6Bq for238U(0.48ng).1.3 This standard does not purport to address all of thesafety problems,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:2D1193 Specification for Reagent WaterC1475 Guide for Determination of Neptunium-237 in SoilC859 Terminology Relating to Nuclear MaterialsC1379 Test Method for Analysis of Urine for Uranium-235and Uranium-238 Isotopes by Inductively CoupledPlasma-Mass SpectrometryD4962 Practice for NaI(Tl)Gamma-Ray Spectrometry ofWater3.Terminology3.1 Definitions:3.1.1 Definitions not found in C859 Terminology Relatingto Nuclear Materials:3.1.2 Instrument check standardstandard solutions evalu-ated at specified intervals during batch analysis to evaluateinstrument calibration stability during analysis.3.1.3 Internal standardsolutions added to each calibrationstandard,check standard,and sample for the purpose ofmonitoring and correcting for instrument drift,due to aerosoltransport effects,nebulizer blockage,ion sampling orificeblockage and matrix enhancement or suppression.3.1.4 Isobarany nuclide that has the same atomic massnumber as another nuclide,but a different atomic number3.1.5 Isotope dilution analysisisotope ratio measurementsof samples spiked with accurately known weights of individuallow abundance isotopes3.2 Acronyms:ICP-MSICP-MS=Inductively Coupled Plasma-Mass SpectrometryPHA=Pulse Height AnalysisLOD=limit of detectionMDC=minimum detectable concentrationLCS=laboratory control standard4.Summary of Practice4.1 An aliquot of a urine sample is spiked with239Np,230Thand233U tracers followed by wet ashing with nitric acid andhydrogen peroxide.After re-dissolution in nitric acid contain-ing aluminum nitrate and sodium nitrite,the analytes areextracted using an extraction chromatography resin.For analy-sis by ICP-MS the eluent is spiked with242Pu internal standardfollowed by wet ashing with nitric acid and re-dissolution in 5mL 5%nitric acid.4.2232Th,235U and238U are determined using ICP-MSisotopic dilution techniques.Chemical yield(recovery)mea-surements indicate a typical yield of 75-85%for these ana-lytes.The isotopic composition of uranium is determined byICP-MS isotopic ratio measurements.237Np is determined byICP-MS using external standardization combined with239Nprecovery measurements(85-95%)using gamma-ray spectrom-etry.1This practice is under the jurisdiction of ASTM Committee C26 on NuclearFuel Cycle and is the responsibility of Subcommittee C26.05 on Methods of Test.Current edition approved Oct.1,2010.Published October 2010.Originallyapproved in 2005.Last previous edition approved in 2005 as C1614-05.DOI:10.1520/C1614-05R10.2For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesNOTICE:This standard has either been superseded and replaced by a new version or withdrawn.Contact ASTM International(www.astm.org)for the latest information1 5.Significance and Use5.1 This practice may be used as part of a bioassay programfor workers potentially exposed to nuclear material by mea-suring237Np,232Th and235U and238U in their urine samples.ICP-MS has been used to analyze for many actinides inhigh-level radioactive wastes(1)3,in soils(2)as well asuranium in urine(Test Method C1379).237Np and239Puanalysis by ICP-MS in bioassay samples has also been reported(3).5.2 Several days counting times are required for alpha-particle analysis of237Np,232Th and235U and238U whereasICP-MS requires only four minutes per sample.Alpha-particlecounting methods for neptunium may also require the use of239Pu as a radiotracer for determina