ASTM_D_6584_-_13e1.pdf

Designation:D6584131Standard Test Method forDetermination of Total Monoglycerides,Total Diglycerides,Total Triglycerides,and Free and Total Glycerin in B-100Biodiesel Methyl Esters by Gas Chromatography1This standard is issued under the fixed designation D6584;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.1NOTEThe formats of Eq 11 and Eq 16 were editorially corrected in April 2014.1.Scope*1.1 This test method covers the quantitative determinationof total monoglyceride,total diglyceride,total triglyceride,andfree and total glycerin in B-100 methyl esters by gas chroma-tography.The range of quantitation for monoglyceride is 0.009to 0.77860 mass%,for diglyceride is 0.092353 to 0.54475mass%,and for triglyceride is 0.00092857 to 1.3881 mass%.The range of quantitation for free glycerin is 0.0005714 to0.019533 mass%and for total glycerin from 0.0090714 to0.42767 mass%.This procedure is not applicable to vegetableoil methyl esters obtained from lauric oils,such as coconut oiland palm kernel oil.1.2 The values stated in SI units are to be regarded asstandard.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:2D4307 Practice for Preparation of Liquid Blends for Use asAnalytical StandardsE355 Practice for Gas Chromatography Terms and Relation-shipsE594 Practice for Testing Flame Ionization Detectors Usedin Gas or Supercritical Fluid Chromatography3.Terminology3.1 Definitions:3.1.1 biodiesel(B-100),nfuel comprised of mono-alkylesters of long chain fatty acids derived from vegetable oils oranimal fats.3.1.2 bonded glycerin,nglycerin portion of the mono-,di-,and triglyceride molecules.3.2 Definitions of Terms Specific to This Standard:3.2.1 total glycerin,nsum of free and bonded glycerin.3.3 This test method makes reference to many common gaschromatographic procedures,terms,and relationships.Detaileddefinitions can be found in Practices E355 and E594.4.Summary of Test Method4.1 The sample is analyzed by gas chromatography,aftersilyating with N-methyl-N-trimethylsilyltrifluoracetamide(MSTFA).Calibration is achieved by the use of two internalstandards and four reference materials.Mono-,di-,and triglyc-eride are determined by comparing to monoolein,diolein,andtriolein standards respectively.Average conversion factors areapplied to mono-,di-,and triglycerides to calculate the bondedglycerin content of the sample.5.Significance and Use5.1 Free and bonded glycerin content reflects the quality ofbiodiesel.A high content of free glycerin may cause problemsduring storage,or in the fuel system,due to separation of theglycerin.A high total glycerin content can lead to injectorfouling and may also contribute to the formation of deposits atinjection nozzles,pistons,and valves.6.Apparatus6.1 Chromatographic SystemSee Practice E355 for spe-cific designations and definitions.6.1.1 Gas Chromatograph(GC)The system must be ca-pable of operating at the conditions given in Table 1.6.1.2 Column,open tubular column with a 5%phenylpo-lydimethylsiloxane bonded and cross linked phase internal1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products,Liquid Fuels,and Lubricants and is the direct responsibility ofD02.04.0L on Gas Chromatography Methods.Current edition approved May 1,2013.Published May 2013.Originallyapproved in 2000.Last previous edition approved in 2010 as D658410a1.DOI:10.1520/D6584-13E01.2For 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.*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 States1 coating.The column should have an upper temperature limit ofat least 400C.Columns,either 10 m or 15 m in length,with a0.32 mm internal diameter,and a 0.1 m film thickness havebeen found satisfactory.Any column with better or equivalentchromatographic efficiency and selectivity can be used.It isrecommended that a 2 to 5 metre 0.53 mm high temperatureguard column be installed from the injector to the analyticalcolumn.This allows the use of autoinjectors and also increasescolumn life.6.2 Electronic Data Acquisition System:6.2.1 Integrator or Computer,capable of providing real timegraphic and digital presentation of the chromatographic data isrecommended