1、Designation:D242706(Reapproved 2015)Standard Test Method forDetermination of C2through C5Hydrocarbons in Gasolinesby Gas Chromatography1This standard is issued under the fixed designation D2427;the number immediately following the designation indicates the year oforiginal adoption or,in the case of
2、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 the determination of the two(C2)through five(C5-)carbon paraffins and mono-ole
3、fins ingasolines.The concentrations by volume or mass(weight)ofthe following components are generally reported:1.1.1 Ethylene plus ethane1.1.2 Propane1.1.3 Propylene1.1.4 Isobutane1.1.5 n-Butane1.1.6 Butene-1 plus isobutylene1.1.7 trans-Butene-21.1.8 cis-Butene-21.1.9 Isopentane1.1.10 3-Methylbutene
4、-11.1.11 n-Pentane1.1.12 Pentene-11.1.13 2-Methylbutene-11.1.14 trans-Pentene-21.1.15 cis-Pentene-21.1.16 2-Methylbutene-21.2 This test method does not cover the determination ofcyclic olefins,diolefins,or acetylenes.These are usually minorcomponents in finished gasolines.1.3 Samples to be analyzed
5、should not contain significantamounts of material boiling lower than ethylene.1.4 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.4.1 ExceptionAlternative units,in common usage,arealso provided to improve the clarity and aid th
6、e user of this testmethod.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
7、 to use.2.Referenced Documents2.1 ASTM Standards:2D2001 Test Method for Depentanization of Gasoline andNaphthas3.Summary of Test Method3.1 The sample is injected into a gas-liquid partition col-umn.The components are separated as they pass through thecolumn with an inert carrier gas and their presen
8、ce in theeffluent is detected and recorded as a chromatogram.Materialscontaining components having more than five carbon atomscaneitherbebackflushedfromthesystemwithoutmeasurement,or recorded as a broad peak by reversing thedirection of the carrier gas through the column at such time asto regroup th
9、e higher-boiling portion(C6and heavier)of thesample.If backflushing is used,the concentration of C2through C5hydrocarbons may be related to the whole sampleby adding a known quantity of low-boiling internal standard tothe sample prior to analysis.Alternatively,a known amount ofsample can be charged
10、and compared to a standard sample rununder the same conditions.Sample composition is determinedfrom the chromatogram by comparing peak areas with thoseobtained using known amounts of calibration standards or asynthetic blend.4.Significance and Use4.1 In hydrocarbon type analyses of gasolines,highly
11、vola-tile fuels can need to be stabilized by depentanization(TestMethod D2001)prior to analysis.A knowledge of the compo-sition of light hydrocarbons in the overhead from the depen-tanization process is useful in converting analyses of thedepentanized fraction to a total sample basis.5.Apparatus5.1
12、ChromatographAny chromatograph having a thermo-stated oven and a detection system of adequate sensitivity may1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products,Liquid Fuels,and Lubricants and is the direct responsibility ofSubcommittee D02.04.0L on Gas Chromatogra
13、phy Methods.Current edition approved Oct.1,2015.Published December 2015.Originallyapproved in 1965.Last previous edition approved in 2011 as D2427 06(2011).DOI:10.1520/D2427-06R15.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.Fo
14、r 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.United States1 be used.The detection system must have sufficient sensitivityto produce a re
15、corder deflection of at least 5 mm for 0.1 liquidvolume percent of pentene-1 in the sample or synthetic blendbeing analyzed.NOTE1If the sensitivity of a given system is inadequate,it can beincreased by using a more sensitive recorder or detector,or by using moresample if the resolution is substantia
16、lly unaffected.5.2 RecorderA 1 mV to 10 mV recorder with a full-scaleresponse time of 2 s or less and a noise level no greater than60.3%of full scale.5.3 Columns:5.3.1 A description of columns and valving arrangementsthat meet the requirements of this method are described inAnnex A1.Persons using other column materials must estab-lish that the column gives results that meet the precisionrequirements of Section 10.5.3.2 Analyzer ColumnThe column system used must becapable of resolving the individ
