ASTM_D_7593_-_14.pdf

Designation:D759314Standard Test Method forDetermination of Fuel Dilution for In-Service Engine Oils byGas Chromatography1This standard is issued under the fixed designation D7593;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 fueldilution for in-service engine oil by gas chromatography.1.2 Analysis can be performed directly by this test methodwithout pretreatment or dilution of the sample.1.3 There is no limitation for the determination of thedilution range,provided the amount of sample is within thelinear range of the gas chromatograph detector.However,sample dilution can add potential error to the result and mayaffect the precision obtained as compared to the values pre-sented in Section 14,which were obtained with no dilution.1.4 This test method covers a quantitation range up to 10%(m/m)for diesel and biodiesel,and up to 5%(m/m)forgasoline.1.5 The values stated in SI units are to be regarded asstandard.Where non-SI units are provided,they are shown inparentheses.1.6 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:2D86 Test Method for Distillation of Petroleum Products atAtmospheric PressureD3524 Test Method for Diesel Fuel Diluent in Used DieselEngine Oils by Gas ChromatographyD3525 Test Method for Gasoline Diluent in Used GasolineEngine Oils by Gas ChromatographyE355 Practice for Gas Chromatography Terms and Relation-shipsE594 Practice for Testing Flame Ionization Detectors Usedin Gas or Supercritical Fluid ChromatographyE1510 Practice for Installing Fused Silica Open TubularCapillary Columns in Gas Chromatographs3.Terminology3.1 Definitions:3.1.1 This test method makes reference to common gaschromatographic procedures,terms,and relationships.Detaileddefinitions of these can be found in Practices E355 and E594.3.1.2 fuel dilution,nthe amount,expressed as apercentage,of engine fuel found in the in-service lubricatingoil.3.1.3 fuel diluent,nin service oil analysis,is the unburnedfuel components that enter the engine crankcase causingdilution of the oil.3.1.4 in-service oil,nlubricating oil that is present in amachine that has been at operating temperature for at least onehour.3.1.5 Marker Peak(MP),na marker peak is a chromato-graphic peak used to differentiate sections of a chromatogramby retention time.3.1.5.1 DiscussionFor example,components that elutebefore this marker peak may be considered“fuel,”whilecomponents that elute after this marker peak would be consid-ered“oil.”This marker peak retention time could also serve asthe timing for physical changes in the chromatographic system,such as the time to initiate a valve change or a back-flush.3.2 Abbreviations:3.2.1 A common abbreviation of carbon compounds is todesignate the number of carbon atoms in the compound.Aprefix is used to designate the carbon chain form,while asubscripted suffix denotes the number of carbon atoms.Forexample,normal eicosane=n-C20.4.Summary of Test Method4.1 A representative aliquot of in-service engine oil isintroduced into a gas chromatograph through a programmablesplit injector.Carrier gas transports the vaporized aliquotthrough the dimethyl polysiloxane bonded phase capillary1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products,Liquid Fuels,and Lubricants and is the direct responsibility ofSubcommittee D02.96.02 on Chemistry for the Evaluation of In-Service Lubricants.Current edition approved Oct.1,2014.Published October 2014.Originallyapproved in 2013.Last previous edition approved in 2013 as D7593 13.DOI:10.1520/D7593-14.2For 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 column where the hydrocarbons are separated by the chromato-graphic process.Once the hydrocarbons of interest are sensedby the flame ionization detector,the carrier gas pressure/flow atthe head of the column is lowered and an auxiliary gas supplylocated at the end of the column is increased.The change inpressure forces the direction of the carrier gas to reversedirection and flow back through the injector.The residualhydrocarbons on the column are back-flushed out of theinjector through a charcoal trap and