ASTM_D_7536_-_20.pdf

Designation:D753620Standard Test Method forChlorine in Aromatics by Monochromatic WavelengthDispersive X-ray Fluorescence Spectrometry1This standard is issued under the fixed designation D7536;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.Scope*1.1 This test method covers the determination of chlorine bymonochromatic wavelength-dispersive X-ray fluorescence(MWDXRF)spectrometry in aromatic hydrocarbons,theirderivatives,and related chemicals.1.2 This test method is applicable to samples with chlorineconcentrations to 10 mg/kg.Higher chlorine concentrationscan be determined by quantitatively diluting the sample with asuitable solvent.The limit of detection(LOD)is 0.2 mg/kg andthe limit of quantitation is 0.7 mg/kg.With careful analyticaltechnique or the measurement of replicates,or both,thismethod can be used to successfully analyze concentrationsbelow the LOD.NOTE1The maximum is the highest concentration from the inter-laboratory study(ILS)and the LOD and LOQ were calculated fromPerformance Testing Program(PTP)data.See Table 3.1.3 In determining the conformance of the test results usingthis method to applicable specifications,results shall berounded off in accordance with the rounding-off method ofPractice E29.1.4 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.5 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 information,see Section 9.1.6 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:2D3437 Practice for Sampling and Handling Liquid CyclicProductsD4790 Terminology of Aromatic Hydrocarbons and RelatedChemicalsD6809 Guide for Quality Control and Quality AssuranceProcedures for Aromatic Hydrocarbons and Related Ma-terialsE29 Practice for Using Significant Digits in Test Data toDetermine Conformance with SpecificationsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method2.2 Other Documents:3OSHA Regulations,29 CFR paragraphs 1910.1000 and1910.12003.Terminology3.1 See Terminology D4790 for definitions of terms used inthis test method.4.Summary of Test Method4.1 A monochromatic X-ray beam with a wavelength suit-able to excite the K-shell electrons of chlorine is focused ontoa test specimen contained in a sample cell(see Fig.1).Thefluorescent K radiation at 0.473 nm(4.73)emitted bychlorine is collected by a fixed monochromator(analyzer).Theintensity(counts per second)of the chlorine X-rays is mea-sured using a suitable detector and converted to the concen-tration of chlorine(mg/kg)in a test specimen using a calibra-tion equation.Excitation by monochromatic X-rays reducesbackground,simplifies matrix correction and increases the1This test method is under the jurisdiction of ASTM Committee D16 onAromatic,Industrial,Specialty and Related Chemicals and is the direct responsi-bility of Subcommittee D16.04 on Instrumental Analysis.Current edition approved Aug.15,2020.Published August 2020.Originallyapproved in 2009.Last previous edition approved in 2016 as D7356 16.DOI:10.1520/D7536-20.2For 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 U.S.Government Printing Office Superintendent of Documents,732 N.Capitol St.,NW,Mail Stop:SDE,Washington,DC 20401,http:/www.access.gpo.gov.*A Summary of Changes section appears at the end of this standardCopyright 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.signal/background ratio compared to polychromatic excitationused in conventional WDXRF techniques.45.Significance and Use5.1 This test method provides for the precise measurementof the chlorine content of aromatics with minimal samplepreparation and analyst inv