1、Designation:D759112(Reapproved 2017)Standard Test Method forDetermination of Free and Total Glycerin in BiodieselBlends by Anion Exchange Chromatography1This standard is issued under the fixed designation D7591;the number immediately following the designation indicates the year oforiginal adoption o
2、r,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.Scope1.1 This test method covers and describes an anion ex-change chromatography procedure for
3、 determining free andtotal glycerin content of biodiesel(B100)and blends(B0 toB20)with diesel fuel oils defined by Specification D975Grades 1-D,2-D,and low sulfur 1-D and 2-D and SpecificationD6751(for B100 feedstocks).It is intended for the analysis ofbiodiesel and blend samples containing between
4、0.5 mg kg to50 mgkg glycerin.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 s
5、tandard to establish appro-priate safety and health practices and determine the applica-bility 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
6、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:2D975 Specification for Diesel Fuel OilsD1193 Specification for Reagent WaterD4057 Practice for Manual Sa
7、mpling of Petroleum andPetroleum ProductsD4177 Practice for Automatic Sampling of Petroleum andPetroleum ProductsD6299 Practice for Applying Statistical Quality Assuranceand Control Charting Techniques to Evaluate AnalyticalMeasurement System PerformanceD6751 Specification for Biodiesel Fuel Blend S
8、tock(B100)for Middle Distillate FuelsD6792 Practice for Quality Management Systems in Petro-leum Products,Liquid Fuels,and Lubricants TestingLaboratoriesE177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE691 Practice for Conducting an Interlaboratory Study toDetermine the Prec
9、ision of a Test Method3.Terminology3.1 Definitions:3.1.1 free glycerin,nmeasure of the amount of glycerinremaining in the fuel.3.1.2 total glycerin,nsum of the free glycerin and theglycerin portion of any unreacted or partially reacted oil or fat.4.Summary of Test Method4.1 Free GlycerinA small volu
10、me of an extract of theblend sample is directly injected into an ion chromatographconsisting of appropriate ion exchange columns and into anelectrochemical detector.Glycerin is separated based on itsaffinity for ion exchange sites of the resin with respect to theresins affinity for the eluent.An ele
11、ctrochemical detector isemployed for detection of glycerin.Glycerin is quantified bypeak area based on an external calibration curve,and isreported as g/g(mg/kg),or may be converted to wt%.Calibration standards are prepared from commercially avail-able glycerin(99+%purity)in an aqueous solution.4.2
12、Total GlycerinA small volume extract of a saponifiedblend sample is directly injected into an ion chromatographconsisting of appropriate ion exchange columns and into anelectrochemical detector.Glycerin is separated based on itsaffinity for ion exchange sites of the resin with respect to theresins a
13、ffinity for the eluent.An electrochemical detector isemployed for detection of glycerin.Glycerin is quantified bypeak area based on an external calibration curve,and isreported as g/g(mg/kg),or may be converted to wt%.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Prod
14、ucts,Liquid Fuels,and Lubricants and is the direct responsibility ofSubcommittee D02.04.0C on Liquid Chromatography.Current edition approved May 1,2017.Published July 2017.Originally approvedin2012.Lastpreviouseditionapprovedin2012asD7591 12.DOI:10.1520 D7591-12R17.2For referenced ASTM standards,vis
15、it 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.Unite
16、d 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.1 Calibration standards are prepared from commercially avail-able glycerin(99+%purity)in an aqueous solution.5.Significance and Use5.1 Petroleum-based diesel may be blended with
