1、Designation: D7096 10Standard Test Method forDetermination of the Boiling Range Distribution of Gasolineby Wide-Bore Capillary Gas Chromatography1This standard is issued under the fixed designation D7096; the number immediately following the designation indicates the year oforiginal adoption or, in
2、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 boilingrange distribution of gasol
3、ine and liquid gasoline blendingcomponents. It is applicable to petroleum products and frac-tions with a final boiling point of 280C (536F) or lower, asmeasured by this test method.1.2 This test method is designed to measure the entireboiling range of gasoline and gasoline components with eitherhigh
4、 or low vapor pressure and is commonly referred to asSimulated Distillation (SimDis) by gas chromatographers.1.3 This test method has been validated for gasoline con-taining ethanol. Gasolines containing other oxygenates are notspecifically excluded, but they were not used in the develop-ment of thi
5、s test method.1.4 This test method can estimate the concentration ofn-pentane and lighter saturated hydrocarbons in gasoline.1.5 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.5.1 Results in degrees Fahrenheit can be obtained
6、 bysimply substituting Fahrenheit boiling points in the calculationof the boiling point-retention time correlation.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
7、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 PressureD2421 Practice for Interconversion of Analysis of C5andLighter Hydrocarbons to G
8、as-Volume, Liquid-Volume, orMass BasisD3700 Practice for Obtaining LPG Samples Using a Float-ing Piston CylinderD3710 Test Method for Boiling Range Distribution ofGasoline and Gasoline Fractions by Gas ChromatographyD4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD4307 Practice
9、for Preparation of Liquid Blends for Use asAnalytical StandardsD4626 Practice for Calculation of Gas ChromatographicResponse FactorsD4814 Specification for Automotive Spark-Ignition EngineFuelD4815 Test Method for Determination of MTBE, ETBE,TAME, DIPE, tertiary-Amyl Alcohol and C1to C4Alco-hols in
10、Gasoline by Gas ChromatographyD5191 Test Method for Vapor Pressure of Petroleum Prod-ucts (Mini Method)D5599 Test Method for Determination of Oxygenates inGasoline by Gas Chromatography and Oxygen SelectiveFlame Ionization DetectionD6300 Practice for Determination of Precision and BiasData for Use i
11、n Test Methods for Petroleum Products andLubricantsE594 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 area slice, narea
12、under a chromatogram within aspecified retention time interval.3.1.2 final boiling point (FBP), nthe point at which acumulative volume count equal to 99.5 % of the total volumecounts under the chromatogram is obtained.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Prod
13、ucts and Lubricants and is the direct responsibility of SubcommitteeD02.04.0H on Chromatographic Distribution Methods.Current edition approved Feb. 15, 2010. Published May 2010. Originallyapproved in 2005. Last previous edition approved in 2005 as D709605. DOI:10.1520/D7096-10.2For referenced ASTM s
14、tandards, 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.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM I
15、nternational, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.1.3 initial boiling point (IBP), nthe point at which acumulative volume count equal to 0.5 % of the total volumecounts under the chromatogram is obtained.3.1.4 relative volume response factor (RVRF),
16、nthe vol-ume response factor (see 3.1.8) of a component i relative to thevolume response factor of n-heptane.3.1.5 slice time, nthe retention time at the end of a givenarea slice.3.1.6 slice width, nthe fixed duration (1 s, or less) of theretention time intervals into which the chromatogram is di-vi
17、ded. It is determined from the reciprocal of the frequencyused in the acquisition of data.3.1.7 volume count, nthe product of a slice area (or anarea under a peak) and a volume response factor.3.1.8 volume response factor, na constant of proportion-ality that relates the area under a chromatogram to
18、 liquidvolume.4. Summary of Test Method4.1 The sample is vaporized and transported by carrier gasinto a non-polar, wide-bore capillary gas chromatographiccolumn. The column temperature is raised at a reproducible,linear rate so as to elute the hydrocarbon components in boilingpoint order for measure
19、ment by a flame ionization detector.Conditions are selected such that n-pentane and lighter satu-rated hydrocarbons in the calibration mixture are resolveddiscretely. Linear correlation between hydrocarbon boilingpoint and retention time is established using a known mixtureof hydrocarbons covering t
20、he boiling range expected in thesample. Area slices are converted to volume using theoreticalhydrocarbon volume response factors. Oxygenated samplesrequire experimental determination of oxygenate responsefactors.5. Significance and Use5.1 The determination of the boiling range distribution ofgasolin
21、e by gas chromatographic simulated distillation pro-vides an insight into the composition of the components fromwhich the gasoline has been blended. Knowledge of the boilingrange distribution of gasoline blending components is usefulfor the control of refinery processes and for the blending offinish
22、ed gasoline.5.2 The determination of the boiling range distribution oflight hydrocarbon mixtures by gas chromatographic simulateddistillation has better precision than the conventional distilla-tion by Test Method D86. Additionally, this test methodprovides more accurate and detailed information abo
23、ut thecomposition of the light ends. The distillation data produced bythis test method are similar to that which would be obtainedfrom a cryogenic, true boiling point (15 theoretical plates)distillation.5.3 This test method is intended to expand upon TestMethod D3710 by defining mandatory response f
24、actors, use ofcapillary column technology, inclusion of oxygenates, and useof flame ionization detection.6. Interferences6.1 Ethanol or other oxygenates may coelute with hydrocar-bons present in the sample. Since the response of oxygenates issubstantially different from the response of hydrocarbons,
25、response factors are used to correct the area slice for the elutioninterval of oxygenates.6.2 Concentrations of n-pentane and lighter saturated com-pounds may be estimated from the analysis. However, earlyeluting olefins present in the gasoline samples may coelutewith these compounds.7. Apparatus7.1
26、 Gas ChromatographAny gas chromatograph (GC)designed for use with wide-bore (0.53 mm inside diameter)capillary columns, that meets the performance criteria specifiedin Section 11, and has the following features may be used.Typical operating conditions are shown in Table 1.7.1.1 Column Oven Temperatu
27、re ProgrammingThe gaschromatograph shall be capable of linear temperature-programmed operation from 40 to 280C at rates up to25C/min.7.1.2 Injection PortThe injection port shall be capable ofoperation at temperatures required to completely volatize andtransfer the sample to the GC column. Non-splitt
28、ing orsplit/splitless vaporizing sample ports optimized for use withwide-bore capillary columns are acceptable. If using a splitinlet port, it should be designed to provide a linear sample splitinjection.7.1.3 Flame Ionization DetectorThe detector shall beoptimized for the use of wide-bore capillary
29、 gas chromato-graphic columns and shall conform to the specifications asdescribed in Practice E594.7.1.4 Carrier Gas ControlsThe associated carrier gascontrols shall be of sufficient precision to produce reproduciblecolumn flows in order to maintain analytical integrity.7.1.5 Baseline CorrectionThe
30、gas chromatograph (or an-other component of the gas chromatographic system) shall becapable of subtracting the area slice of a blank run from thecorresponding area slice of a sample run. This can be doneinternally on some gas chromatographs (baseline compensa-tion) or externally by subtracting a sto
31、red, digitized signal froma blank run.TABLE 1 Typical Operating Conditions for Wide BoreColumn InletsColumn length (m) 30 15Column I.D. (mm) 0.53 0.53Stationary phase 100 % poly-dimethylsiloxane100 % poly-dimethylsiloxaneFilm thickness (m) 5 5Carrier gas helium heliumCarrier flow (mL/min) 20 15Auxil
32、iary flow (mL/min) 10 10Column initial temperature (C) 40 40Initial time (min) 1 1Program rate (C/min) 25 20Final temperature (C) 265 230Final hold (min) 4.00 2.50Injection inlet purged-packed purged-packedSample introduction auto syringe injection auto syringe injectionInjector temperature (C) 250
33、250Detector temperature (C) 280 300Hydrogen flow (mL/min) 45 30Air flow (mL/min) 450 300Sample size (L) 0.1 0.2 0.2Area slice width (s) 0.5 0.2 0.5 0.2Datarate(Hz) 25 25D7096 1027.2 Sample IntroductionSample introduction may be bymeans of a constant volume liquid sample valve or by injectionwith a m
34、icro syringe through a septum. An automatic sampleintroduction device is essential to the reproducibility of theanalysis. Manual injections are not recommended. Poor injec-tion technique can result in poor resolution. If column overloadoccurs, peak skewing may result, leading to variation inretentio
35、n times.7.2.1 Samples with a vapor pressure (VP) of less than 16psia as measured by Test Method D5191, or equivalent, may beintroduced into the gas chromatograph by syringe injection intoa heated, vaporizing inlet. Samples with vapor pressuresbetween 12 and 16 psia should be kept chilled (refrigerat
36、ed orin a cooled sample tray) and may require injection with acooled syringe. Samples with a vapor pressure above 16 psiashould be introduced by way of a constant volume liquidsampling valve. Refer to 9.1 for sampling practices.7.3 ColumnAny wide bore (0.53 mm inside diameter)open tubular (capillary
37、) column, coated with a non-polar(100 % polydimethylsiloxane) phase that meets the perfor-mance criteria of 11.3 may be used. Columns of 15 to 30 metrelengths with a stationary phase film thickness of 5.0 m havebeen successfully used. With either of these columns, initialcryogenic temperatures are n
38、ot necessary.7.4 Data Acquisition SystemA computer provided with amonitor, printer, and data acquisition software is necessary tocarry out this analysis. The computer should have sufficienthardware capacity and random access memory in order to runthe data acquisition program while acquiring data at
39、a fre-quency of 2 to 5 Hz. The software should also be able to storethe data for future recall, inspection, and analysis. The dataacquisition software should be capable of presenting a real timeplot. It may also be capable of controlling the operatingvariables of the gas chromatograph. Specialized s
40、oftware isnecessary to obtain the boiling point distribution.7.5 Bulk Sample Containers, floating piston cylinders (see9.1.1); epoxy phenolic-lined metal cans; glass bottles withpolytetrafluoroethylene-lined screw caps.8. Reagents and Materials8.1 Calibration MixtureAsynthetic mixture of pure liquid
41、hydrocarbons with boiling points that encompass the boilingrange of the sample shall be used for retention time determi-nation and response factor validation. Response factors forpropane, isobutane, and n-butane are extrapolated from therelative molar response of the n-paraffins. An example of arela
42、tive response factor mixture with suggested nominal com-position is given in Table 3. This mixture shall be accuratelyTABLE 2 Typical Operating Conditions for Capillary Column InletColumn length (m) 30Column I.D. (mm) 0.53Stationary phase 100 % polydimethylsiloxaneFilm thickness 5 mCarrier gas heliu
43、m (ramped flow)Carrier flow (mL/min) 5mL/min (0.5 min) to 20mL/min 60mL/minColumn initial temperature (C) 40Initial time (min) 1Program rate (C/min) 25Final temperature (C) 245Final hold (min) 4Injection port splitSample introduction automatic syringe injectionInjector temperature (C) 250Detector te
44、mperature (C) 250Hydrogen flow (mL/min) 30Air flow (mL/min) 300Sample size (L) 1 uLSplit ratio 1:50Data rate 5 HzTABLE 3 Typical Calibration Mixture Composition and Properties of HydrocarbonsCompoundBPARelative DensityA15.6/15.6C(60/60F)NominalMass%Approx.BVol%FIDCRVRFC FPropaneD-42.1 -43.8 0.5070 1
45、.394IsobutaneD-11.8 10.8 0.5629 1.241n-ButaneD-0.51 31.1 0.5840 1.196Isopentane 27.8 82.1 0.6247 2.5 3.1 1.111n-Pentane 36.1 96.9 0.6311 3.0 3.7 1.0992-Methylpentane 60.3 140.5 0.6578 4.0 4.7 1.050n-Hexane 68.7 155.7 0.6638 3.0 3.5 1.0402,4-Dimethylpentane 80.5 176.9 0.6764 5.5 6.3 1.017n-Heptane 98
46、.4 209.2 0.6882 7.5 8.4 1.000Toluene 110.6 231.1 0.8743 15.5 13.7 0.724n-Octane 125.7 258.2 0.7070 7.0 7.6 0.971p-Xylene 138.4 281.1 0.8666 16.0 14.2 0.736n-Propylbenzene 159.2 318.6 0.8683 6.5 5.8 0.739n-Decane 174.1 345.5 0.7342 4.5 4.7 0.932n-Butylbenzene 183.3 361.9 0.8660 6.0 5.3 0.745n-Dodecan
47、e 216.3 421.4 0.7527 3.5 3.6 0.907n-Tridecane 235.5 455.8 0.7617 4.5 4.6 0.895n-Tetradecane 253.6 488.4 0.7633 3.0 3.0 0.893n-Pentadecane 270.7 519.2 0.7722 5.0 5.0 0.882n-Hexadecane 286.9 548.3 0.7772 3.0 3.0 0.876ANormal boiling points and relative densities (15.6/15.6C) obtained from Physical Con
48、stants of Hydrocarbon and Non-Hydrocarbon Compounds, ASTM Data SeriesDS 4B, 1988. The Fahrenheit values have been rounded to the nearest 0.1F. The Centigrade column has been converted from the F values prior to rounding as listedin ASTM Data Series DS 4B.BVolume percent is calculated as mass percent
49、 divided by specific gravity, then normalized to 100 volume percent.CFID volume response factors, as specified for use with this test method, are calculated from theoretical mass response factors and are relative to n-heptane (RVRF=1).DNecessary if sample is expected to contain components boiling lower than isopentane. These gases are added non-quantitatively to the liquid calibration mixture.D7096 103prepared on a mass basis using Practice D4307 or equivalent.8.1.1 Asingle calibration standard may be used for reten
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