ASTM_D_6550_-_15.pdf

Designation:D655015Standard Test Method forDetermination of Olefin Content of Gasolines bySupercritical-Fluid Chromatography1This standard is issued under the fixed designation D6550;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 the totalamount of olefins in blended motor gasolines and gasolineblending stocks by supercritical-fluid chromatography(SFC).Results are expressed in terms of mass%olefins.Theapplication range is from 1 mass%to 25 mass%total olefins.1.2 This test method can be used for analysis of commercialgasolines,including those containing varying levels ofoxygenates,such as methyl tert/butyl ether(MTBE),diisopro-pyl ether(DIPE),methyl tert/amyl ether(TAME),and ethanol,without interference.NOTE1This test method has not been designed for the determinationof the total amounts of saturates,aromatics,and oxygenates.1.3 This test method includes a relative bias section basedon Practice D6708 accuracy assessment between Test MethodD6550 and Test Method D1319 for total olefins in spark-ignition engine fuels as a possible Test Method D6550 alter-native to Test Method D1319 for U.S.EPA regulations report-ing.The Practice D6708 derived correlation equation is onlyapplicable for fuels in the concentration range from 0.2%to26.2%by mass as reported by Test Method D6550.Theapplicable Test Method D1319 concentration range for totalolefins is 0.2%to 27.7%by volume as reported by TestMethod D1319.1.4 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 and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D1319 Test Method for Hydrocarbon Types in Liquid Petro-leum Products by Fluorescent Indicator AdsorptionD4052 Test Method for Density,Relative Density,and APIGravity of Liquids by Digital Density MeterD5186 Test Method for Determination of the AromaticContent and Polynuclear Aromatic Content of DieselFuels and Aviation Turbine Fuels By Supercritical FluidChromatographyD6296 Test Method for Total Olefins in Spark-ignitionEngine Fuels by Multidimensional Gas ChromatographyD6299 Practice for Applying Statistical Quality Assuranceand Control Charting Techniques to Evaluate AnalyticalMeasurement System PerformanceD6708 Practice for Statistical Assessment and Improvementof Expected Agreement Between Two Test Methods thatPurport to Measure the Same Property of a MaterialD6839 Test Method for Hydrocarbon Types,OxygenatedCompounds,and Benzene in Spark Ignition Engine Fuelsby Gas Chromatography3.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 critical pressure,nthe pressure needed to condensea gas to a liquid at the critical temperature.3.1.2 critical temperature,nthe highest temperature atwhich a gaseous fluid can be condensed to a liquid by meansof compression.3.1.3 supercritical fluid,na fluid maintained above itscritical temperature and critical pressure.3.1.4 supercritical-fluid chromatography(SFC),na typeof chromatography that employs a supercritical fluid as themobile phase.4.Summary of Test Method4.1 A small aliquot of the fuel sample is injected onto a setof two chromatographic columns connected in series and1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products,Liquid Fuels,and Lubricants and is the direct responsibility ofSubcommittee D02.04.0C on Liquid Chromatography.Current edition approved Dec.1,2015.Published December 2015.Originallyapproved in 2000.Last previous edition approved in 2015 as D6550 10(2015).DOI:10.1520/D6550-15.2For 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 transported using supercritical carbon dioxide(CO2)as themobile phase.The first column is packed with high-surface-area silica particles.The second column contains either high-surface-area silica particles loaded with silver ions or strong-cation-exchange material loaded with silver ions.4.2 Two switching valves are used to direct the differentclasses of components through the chromatographic system tothe detector.In a forward-flow mode,saturates(normal andbranched alkanes,cyclic alkanes)pass through bo