ASTM_C_1844_-_16.pdf

Designation:C184416Standard Test Method forDetermination of Uranium in Urine by Inductively CoupledPlasma Mass Spectrometer Following Nitric Acid Dilution1This standard is issued under the fixed designation C1844;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 determination of uranium inurine by Inductively Coupled Plasma Mass Spectrometry(ICP-MS)after dilution in nitric acid.The method is presentedin two parts.Part A describes a method for determination oftotal uranium in urine that does not distinguish betweenuranium isotopes.Part B describes a method that determinesthe ratio of235U to238U(the enrichment)in samples that PartA has shown to contain levels of uranium that the user of thedata considers to be significant.The measurement in Part Bmay be combined with the measurement in Part A to calculatea235U concentration.The enrichment measurement may inturn be used to estimate levels of minor uranium isotopes,inparticular234U,that are important for calculating the internalradiation dose received by an individual exposed to uranium.The estimation of minor isotope concentrations and the calcu-lation of internal dose does not form part of this standard.1.2 UnitsThe values stated in SI units are to be regardedas standard.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:2C859 Terminology Relating to Nuclear MaterialsD1193 Specification for Reagent Water3.Terminology3.1 DefinitionsFor definitions of other standard terms inthis test method,refer to Terminology C859.3.2 Definitions of Terms Specific to This Standard:3.2.1 internal reference standarda solution containingnon-analyte elements that is analyzed by the ICP-MS alongsideall samples.The signal is used to correct for small matrixeffects and instrumental drift during the run to give a moreprecise measurement.The element or elements are selectedsuch that they are not present in the unknown samples atsignificant concentrations,are within the general mass range ofthe measured analytes and have similar chemical behaviors inthe instrument.3.2.2 method blanka solution which in so far as ispractical duplicates the preparation process of the sample to beanalyzed and passes through the same measurement processbut does not initially contain significant quantities of any of theanalytes to be measured.3.2.2.1 DiscussionThe method blank does not initiallycontain significant quantities of analyte,hence the value of anyanalyte measured may be assumed to be due to interference,matrix effects or contamination introduced as a consequence ofsample processing.If the contribution of such factors isevaluated to be representative to the measurement of theunknown samples in the batch then subtracting the measuredvalue for the method blank from the value measured on thegenuine sample will eliminate these interferences,typicallyproviding a better estimate for the true value of the quantity ofanalyte in the sample.3.2.3 spikea known quantity of analyte added to a samplewhich is used to evaluate losses during the sample preparationprocess or biases during measurement.4.Summary of Test Method4.1 For the determination of total uranium in urine:samplesof urine are initially diluted by a factor of 20 with 0.32 M nitricacid(this is a 2%by volume dilution of typical,concentratednitric acid).The diluted sample is then analyzed for totaluranium using an ICP-MS.Prior to analysis of samples theinstrument is calibrated using 0,50,100,and 200 ng/LUranium Standards prepared in 0.32 M nitric acid,that hasbeen prepared using ultra high purity(UHP)concentrated acid.The Certified Reference Materials used for Standard prepara-tion typically contain natural uranium.A method blank is runafter the calibration and all subsequent results are blank1This test method is under the jurisdiction ofASTM Committee C26 on NuclearFuel Cycle and is the direct responsibility of Subcommittee C26.05 on Methods ofTest.Current edition approved Dec.15,2016.Published December 2016.DOI:10.1520/C1844-16.2For 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 States1 corrected.A 50 ng/L Uranium Instrument Quality ControlSample is also analyzed after