ASTM_D_6623_-_01.pdf

Designation:D 6623 01An American National StandardStandard Test Method forDetermination of Individual Components in Spark IgnitionEngine Fuels by High Resolution Gas Chromatography1This standard is issued under the fixed designation D 6623;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(e)indicates an editorial change since the last revision or reapproval.INTRODUCTIONThis test method consists of three individual procedures designated as A,B,and C.Procedure A(Detailed Hydrocarbon Analysis-DHA)was the first procedure submitted to be tested and developedbyASTM.Procedure B(Individual HydrocarbonAnalysis-IHA)is derived from the revised CanadianCAN/CGSB-3.0 No.14-3-94 test method.Procedure C(DHC)is derived and is consistent with theFrench Standard NF M07-086.Procedures A and B employ 100 metre poly(dimethyl)siloxane opentubular capillary columns and procedure C employs a 50 metre poly(dimethyl)siloxane capillarycolumn.In addition,Procedure A requires the use of a short precolumn(injector end)located in theGC oven and connected to the 100 metre capillary column.The precolumn is used to optimizeseparation selectivity.Similar samples were used to obtain the precision statements for Procedures Aand B while the precision for Procedure C was obtained with a different sample set.All threeprocedures used similar ASTM approved statistical procedures for the calculation of the precisionstatements.Although the three procedures share similar instrumentation requirements and practice ofthe gas chromatographic art,the scope as indicated,apparatus description,reagents and materials,system optimization,calibration,calculation and precision sections are presented separately for eachprocedure to allow the user to perform effectively each procedure as practiced in the originalinterlaboratory cooperative study.It is very important that the user of this test method specify clearlywhich procedure(A,B,or C)was used when comparing results with other laboratories or reportingresults.Appendix X1 of this test method contains comparison data for Procedures A and B for severalinterlaboratory cooperative study samples with other types of test methods for several selectedoxygenates and hydrocarbon types.Comparison data for Procedure C is not available since it used adifferent set of gasolines in the round robin.1.Scope1.1 Procedures A and B:1.1.1 Test ProceduresAand B provide for the determinationof individual hydrocarbon components of spark-ignition en-gine fuels and their mixtures containing oxygenate blends(MTBE,ETBE,ethanol,and so forth.)with boiling ranges upto 225C.Other light liquid hydrocarbon mixtures typicallyencountered in petroleum refining operations,such as,blendingstocks(naphthas,reformates,alkylates,and so forth.)may alsobe analyzed;however,statistical data was obtained only withblended spark-ignition engine fuels.1.1.2 Based on the cooperative study results,individualcomponent concentrations and precision are determined in therange of 0.01 to approximately 30%mass percent.Theprocedures may be applicable to higher and lower concentra-tions for the individual components;however,the user shallverify the accuracy if the procedures are used for componentswith concentrations outside the specified ranges.1.1.3 Test Procedures A and B also determine methanol,ethanol,t-butanol methyl t-butyl ether(MTBE),ethyl t-butylether(ETBE),t-amyl-methyl-ether(TAME)in spark ignitionengine fuels in the concentration range of 1 to 30 mass%.However,the cooperative study data provided sufficient statis-tical data for MTBE in Procedure B only.1.1.4 Although a majority of the individual hydrocarbonspresent are determined,some co-elution of compounds isencountered.If this test method is utilized to estimate bulkhydrocarbon group-type composition(PONA)the user of suchdata should be cautioned that some error will be encountereddue to co-elution and a lack of identification of all componentspresent.Samples containing significant amounts of olefinic ornaphthenic,or both(for example,virgin naphthas)constituents1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD.02.04.0L on Hydrocarbon Analysis.Current edition approved March 10,2001.Published May 2001.1Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.NOTICE:This standard has either been superseded and replaced by a new version or withdrawn.Contact ASTMInternational(www.astm.org)for the latest information.above N-octane may reflect significant errors in PONA typegroupings.Based on the gasoline samples in the interlaboratorycooperative study,these procedures are applicable to concen-trations of olefins to less than 25 mass%.However,someinterfering coelution with the olefins above C7