ASTM_D_7754_-_11.pdf

Designation:D775411Standard Test Method forDetermination of Trace Oxygenates in Automotive Spark-Ignition Engine Fuel by Multidimensional GasChromatography1This standard is issued under the fixed designation D7754;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.Scope1.1 This test method covers the determination of traceoxygenates in automotive spark-ignition engine fuel.Themethod used is a multidimensional gas chromatographicmethod using 1,2-dimethoxy ethane as the internal standard.The oxygenates that are analyzed are:methyl-tertiary butylether(MTBE),ethyl-tertiary butyl ether(ETBE),diisopropylether(DIPE),methanol,tertiary-amyl methyl ether(TAME),n-propanol,i-propanol,n-butanol,i-butanol,tert-butyl alcohol,sec-butyl alcohol,and tert-pentanol.Ethanol is usually notmeasured as a trace oxygenate since ethanol can be used as themain oxygenate compound in finished automotive spark-ignition fuels such as reformulated automotive spark-ignitionfuels.The concentration range of the oxygenates covered in theILS study was from 10 g/Kg to 2000 g/Kg.In addition thismethod is also suitable for the measurement of the C5 isomericalcohols(2-methyl-1-butanol,2-methyl-2-butanol)presentfrom the fermentation of ethanol.1.2 The ethanol blending concentration for which this testmethod applies ranges from 1 to 15%by volume.Higherconcentrations of ethanol coelute with methanol in the analyti-cal column.Lower levels of ethanol,similar to the otheroxygenate,can be calibrated and analyzed also.If higherethanol concentrations are expected,the window cutting tech-nique can be used to avoid ethanol from entering the analyticalcolumn and interfere with the determination of the otheroxygenates of interest.Refer to Appendix X1 for details.1.3 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.3.1 Alternate units,in common usage,are also provided toincrease clarity and aid the users of this test method.1.4 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:2D4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD4307 Practice for Preparation of Liquid Blends for Use asAnalytical StandardsD4815 Test Method for Determination of MTBE,ETBE,TAME,DIPE,tertiary-Amyl Alcohol and C1to C4Alco-hols in Gasoline by Gas ChromatographyD6304 Test Method for Determination of Water in Petro-leum Products,Lubricating Oils,and Additives by Cou-lometric Karl Fischer Titration3.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 electronic pressure control,nelectronic pneumaticcontrol of carrier gas flows.Can be flow or pressure pro-grammed to speed up elution of components.3.1.2 flame ionization detector(FID),ndetector used toanalyze the components eluting from the column.3.1.3 fluidic switch,ndevice that reverses the directionalflow in a union T altering the pressure at the midpoint.In itssimplest design it is also known as a Dean Switch.3.1.4 inlet,ncapillary split/splitless inlet system operatedin the split mode is recommended.Operate the inlet within itslinear range.3.1.4.1 split ratio,n in capillary gas chromatography,theratio of the total flow of carrier gas to the sample inlet versusthe flow of the carrier gas to the capillary column is expressedby:Split ratio5S1C!/C(1)1This 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 Chromatography Methods.Current edition approved Oct.1,2011.Published November 2011.DOI:10.1520/D7754112For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 where:S=flow rate at the splitter vent,andC=flow rate at the column outlet.3.1.5 low volume connector,nspecial union for connect-ing two lengths of tubing 1.6-mm inside diameter and smaller.Sometimes this is referred to as zero dead volume union.3.1.6 multidimensional gas chromatography,ngas chro-matographic technique where using hardware(valves,pressureswitches,etc.)in which selected components from one column(primary column)are transferred to a secondary columndiffering in characteristics(film thickness,polarity,capacity,etc.)from the first column.3.1.7 ppm,nparts per mil