ASTM_D_6584_-_21.pdf

Designation:D658421Standard 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.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 is0.009%to 0.77860%by mass,for diglyceride is 0.092353%to 0.54475%by mass,and for triglyceride is 0.00092857%to1.3881%by mass.The range of quantitation for free glycerinis 0.0005714%to 0.019533%by mass and for total glycerinfrom 0.0090714%to 0.42767%by mass.This procedure isnot applicable to vegetable oil methyl esters obtained fromlauric oils,such as coconut oil and 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,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.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:2D4175 Terminology Relating to Petroleum Products,LiquidFuels,and LubricantsD4307 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 This test method makes reference to commonprocedures,terms,and relationships.Detailed definitions ofthese can be found in Practices E355 and E594,and Terminol-ogy D4175.Several definitions for clarity are indicated below:3.1.2 biodiesel(B-100),nfuel comprised of mono-alkylesters of long chain fatty acids derived from vegetable oils oranimal fats.3.1.3 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.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.1This 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 Dec.1,2021.Published January 2022.Originallyapproved in 2000.Last previous edition approved in 2017 as D6584 17.DOI:10.1520/D6584-21.2For 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 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.16.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