ASTM_D_4526_-_20.pdf

Designation:D452620Standard Practice forDetermination of Volatiles in Polymers by Static HeadspaceGas Chromatography1This standard is issued under the fixed designation D4526;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 Headspace gas chromatography(GC)involves the de-termination of volatile components in a polymer solution bygas chromatography of a vapor phase in thermal equilibriumwith the sample matrix.Volatiles in finely ground insolublepolymers can also be determined with and without an extract-ing solvent.1.2 This practice provides two procedures:1.2.1 Procedure AAutomatic headspace analysis.1.2.2 Procedure BManual injection headspace analysis.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.Specific precautionary statements are given in Section 7.NOTE1There is no known ISO equivalent to this standard.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:2D883 Terminology Relating to PlasticsD4322 Test Method for Residual Acrylonitrile MonomerStyrene-Acrylonitrile Copolymers and Nitrile Rubber byHeadspace Gas Chromatography(Withdrawn 2010)3E260 Practice for Packed Column Gas ChromatographyE355 Practice for Gas Chromatography Terms and Relation-shipsE594 Practice for Testing Flame Ionization Detectors Usedin Gas or Supercritical Fluid Chromatography3.Terminology3.1 GeneralThe units,symbols,and abbreviations used inthis test method are in accordance with Terminology D883 andPractice IEEE/ASTM SI-10.4.Significance and Use4.1 There are various reasons why one would measure thelevel of unreacted or residual monomer,water,or other volatilecomponents in a polymer sample.4.2 Volatiles of interest are often at trace concentrations.Headspace analysis is suited for determination of these tracecomponents which often cannot be determined by conventionalgas chromatography because of sample decomposition orinterferences.4.3 For polymer analysis,sample treatment for headspaceanalysis is simpler than conventional gas chromatography,where additional precipitation steps are required to preventpolymer contamination of the chromatographic column.4.4 This headspace practice will be able to determinequalitatively any component with sufficient vapor pressure.Itis capable of yielding semiquantitative results and can be usedfor relative comparisons between samples.5.Apparatus5.1 Gas Chromatograph,equipped with an appropriatedetector and backflush valve.5.1.1 For Procedure A,an Automated Headspace Sampler,including backflush capability,thermostated sample tray,andassociated accessories fulfill these requirements while provid-ing for automatic sequential sampling of headspace vapors.5.1.2 Procedure B requires the following additional equip-ment:5.1.2.1 Constant-Temperature Bath,capable of maintaining90 6 1C.5.1.2.2 Gas-Tight Gas Chromatographic Syringes,whichcan be heated to 90C for sampling and injection.1This practice is under the jurisdiction ofASTM Committee D20 on Plastics andis the direct responsibility of Subcommittee D20.70 on Analytical Methods.Current edition approved May 15,2020.Published June 2020.Originallyapproved in 1985.Last previous edition approved in 2012 as D4526-12.DOI:10.1520/D4526-20.2For 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.3The last approved version of this historical standard is referenced onwww.astm.org.*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.5.1.2.3 Valve,6-port for backflush assembly.NOTE2Appropriate detectors could include the following:(a)Flame ionization(FID)for general organic volatiles,(b)Electron capture(EC)for halogenated species,(c)Nitrogen-phosphorous(NPD)for acryloni