ASTM_D_4785_-_20.pdf

Designation:D478520Standard Test Method forLow-Level Analysis of Iodine Radioisotopes in Water1This standard is issued under the fixed designation D4785;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 quantification of low levelsof radioactive iodine in water by means of chemical separationand counting with a high-resolution gamma ray detector.Iodine is chemically separated from a 4 L water sample usingion exchange and solvent extraction and is then precipitated ascuprous iodide for counting.1.2 The values stated in SI units are to be regarded asstandard.The values given in parentheses after SI units areprovided for information only and are not considered standard.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,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.For specific hazard statements,see 8.16,8.17,8.18,Section 9,and 13.2.11.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D1129 Terminology Relating to WaterD1193 Specification for Reagent WaterD2777 Practice for Determination of Precision and Bias ofApplicable Test Methods of Committee D19 on WaterD3370 Practices for Sampling Water from Flowing ProcessStreamsD3648 Practices for the Measurement of RadioactivityD3649 Practice for High-Resolution Gamma-Ray Spectrom-etry of WaterD4448 Guide for Sampling Ground-Water Monitoring WellsD5847 Practice for Writing Quality Control Specificationsfor Standard Test Methods for Water AnalysisD6001 Guide for Direct-Push Groundwater Sampling forEnvironmental Site CharacterizationD7282 Practice for Set-up,Calibration,and Quality Controlof Instruments Used for Radioactivity MeasurementsD7902 Terminology for Radiochemical Analyses2.2 Other Documents:ANSI N42.22 Traceability of Radioactive Sources to theNational Institute of Standards and Technology(NIST)and Associated Instrument Quality Control3BIPM-5 Decay Data Evaluation Project(DDEP)4NUDAT253.Terminology3.1 Definitions:3.1.1 For definitions of terms used in this standard,refer toTerminology D1129.3.1.2 For definitions of terms used in this standard relatingto radiochemical analysis,refer to Terminology D7902.4.Summary of Test Method4.1 Sodium iodide is added as a carrier prior to performingany chemical separations.The samples undergo an oxidation-reduction process to ensure exchange between the carrier andthe radioactive iodide.Hydroxylamine hydrochloride and so-dium bisulfite are added to convert all the iodine to iodidewhich is then removed by anion exchange.Subsequent elutionof the iodide is followed by oxidation-reduction to elementaliodine.The elemental iodine is purified by solvent extraction,reduced to iodide,and precipitated as cuprous iodide.Thechemical yield is determined from the net mass of recoverediodide carrier.1This test method is under the jurisdiction of ASTM Committee D19 on Waterand is the direct responsibility of Subcommittee D19.04 on Methods of Radiochemi-cal Analysis.Current edition approved May 1,2020.Published June 2020.Originallyapproved in 1988.Last previous edition approved in 2013 as D4785 131.DOI:10.1520/D4785-20.2For 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.3Available from Institute of Electrical and Electronics Engineers,Inc.(IEEE),445 Hoes Ln.,Piscataway,NJ 08854-4141,http:/www.ieee.org.4Available from BIPM,Svres Cedex,France,https:/www.bipm.org.5Available from National Nuclear Data Center at Brookhaven NationalLaboratory,W Princeton Ave,Yaphank,NY 11980,http:/www.nndc.bnl.gov.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.5.Significance and Use5.1 This test method was developed for measuring lowlevels of radioactive iodine in water.The results of the test maybe used to determine if the concentration of