ASTM_C_1296_-_95_2007.pdf

Designation:C 1296 95(Reapproved 2007)Standard Test Method forDetermination of Sulfur in Uranium Oxides and UranylNitrate Solutions by X-Ray Fluorescence(XRF)1This standard is issued under the fixed designation C 1296;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(e)indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers the sample preparation andanalysis by X-ray fluorescence(XRF)of sulfur in uraniumoxides and uranyl nitrate solutions.1.2 This test method is valid for those solutions containing100 to 500 g sulfur/mL.Higher concentrations may bemeasured by appropriate dilutions.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.See Section 9 andNote 1 for specific hazards statements.2.Referenced Documents2.1 ASTM Standards:2C 788 Specification for Nuclear-Grade Uranyl Nitrate So-lution or CrystalsC 967 Specification for Uranium Ore ConcentrateC 982 Guide for Selecting Components for Energy-Dispersive X-Ray Fluorescence(XRF)SystemsC 1118 Guide for Selecting Components for Wavelength-Dispersive X-Ray Fluorescence(XRF)SystemsD 1193 Specification for Reagent WaterE 135 Terminology Relating to Analytical Chemistry forMetals,Ores,and Related Materials2.2Other Documents:NBS Handbook 111,Radiation Safety for X-Ray Diffractionand X-Ray Fluorescence Analysis Equipment33.Terminology3.1 For definitions of terms used in this test method,refer toTerminology E 135.4.Summary of Test Method4.1 Solution standards containing 0(blank)to 500 g sulfurper mL in a matrix of 0.08 g uranium per mL are placed in theliquid sample holder of an X-ray spectrometer and exposed toan X-ray beam capable of exciting the sulfur K-alpha emissionline.The intensity values obtained from these standard solu-tions are used to calibrate the X-ray spectrometer.4.2 Either wavelength-dispersive or energy-dispersiveX-ray fluorescence systems may be used for this analysis.5.Significance and Use5.1 This test method is applicable to uranium solutions,uranium oxides,and other uranium compounds that are solublein nitric acid and contain sulfur up to 5000 g/g sample.Thistest method can be used to determine conformance to specifi-cation for uranium ore concentrate(see Specification C 967),uranium trioxide(UO3),uranium dioxide(UO2),and uranylnitrate(see Specification C 788).For uranium solutions,theuranium content should be between 0.07 g/mL and 0.10 g/mL.6.Interferences6.1 Sulfur X-rays(53.7 nm)are extremely soft(long wave-length)X-rays and are easily absorbed by uranium;therefore,it is important to match the uranium concentration in thestandards and test samples to compensate for this absorptioneffect since no internal standard is used in this test method.Even if the sulfur content of the sample is in the correct range,errors can result if the uranium concentration is not matched.6.2 As with all XRF methods,the choice of X-ray tubetarget is important.Because of the line overlap of molybdenumand sulfur,molybdenum target tubes are not recommended.Chromium,rhodium,and scandium target tubes have beenfound to be satisfactory.6.3 The presence of impurities such as zirconium and cobaltalso should be considered for their interfering effects.Suchconsiderations are outside the scope of this test method.1This 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 Feb.1,2007.Published March 2007.Originallyapproved in 1995.Last previous edition approved in 2001 as C 129695(2001).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 the U.S.Department of Commerce,National Institute ofStandards and Technology,Gaithersburg,MD 20899.1Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.NOTICE:This standard has either been superseded and replaced by a new version or withdrawn.Contact ASTM International(www.astm.org)for the latest information 7.Apparatus7.1 X-ray spectrometerSee Specification C 982 or GuideC 1118 for the selection of the X-ray spectrometer.This testmethod is valid for either energy-dispersive or wavelength-dispersive systems.The system must be equipped with an inertgas flush system(normally helium).(See Section 11 onPreparation of Apparatus.)7.2 Sample cupsPrepare liquid sample cups for the X-rayspectrometer as described by the manufacturer.Vented