1、Designation: D7096 10D7096 16Standard 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
2、 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 the boiling range distribution
3、 of gasoline and liquid gasoline blendingcomponents. It is applicable to petroleum products and fractions with a final boiling point of 280C (536F)280 C (536 F) orlower, as measured by this test method.1.2 This test method is designed to measure the entire boiling range of gasoline and gasoline comp
4、onents with either high orlow vapor pressure and is commonly referred to as Simulated Distillation (SimDis) by gas chromatographers.1.3 This test method has been validated for gasoline containing ethanol. Gasolines containing other oxygenates are notspecifically excluded, but they were not used in t
5、he development of this test method.1.4 This test method can estimate the concentration of n-pentane and lighter saturated hydrocarbons in gasoline.1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.5.1 Results in degrees Fa
6、hrenheit can be obtained by simply substituting Fahrenheit boiling points in the calculation of theboiling point-retention time correlation.1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard
7、to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D86 Test Method for Distillation of Petroleum Products and Liquid Fuels at Atmospheric PressureD2421 Practice for Interconversion of A
8、nalysis of C5 and Lighter Hydrocarbons to Gas-Volume, Liquid-Volume, or Mass BasisD3700 Practice for Obtaining LPG Samples Using a Floating Piston CylinderD3710 Test Method for Boiling Range Distribution of Gasoline and Gasoline Fractions by Gas Chromatography (Withdrawn2014)3D4057 Practice for Manu
9、al Sampling of Petroleum and Petroleum ProductsD4307 Practice for Preparation of Liquid Blends for Use as Analytical StandardsD4626 Practice for Calculation of Gas Chromatographic Response FactorsD4814 Specification for Automotive Spark-Ignition Engine FuelD4815 Test Method for Determination of MTBE
10、, ETBE, TAME, DIPE, tertiary-Amyl Alcohol and C1 to C4 Alcohols inGasoline by Gas ChromatographyD5191 Test Method for Vapor Pressure of Petroleum Products (Mini Method)D5599 Test Method for Determination of Oxygenates in Gasoline by Gas Chromatography and Oxygen Selective FlameIonization DetectionD6
11、300 Practice for Determination of Precision and Bias Data for Use in Test Methods for Petroleum Products and LubricantsE594 Practice for Testing Flame Ionization Detectors Used in Gas or Supercritical Fluid ChromatographyE1510 Practice for Installing Fused Silica Open Tubular Capillary Columns in Ga
12、s Chromatographs1 This test method is under the jurisdiction ofASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of SubcommitteeD02.04.0H on Chromatographic Distribution Methods.Current edition approved Feb. 15, 2010Jan. 1, 2016. Published May 20
13、10February 2016. Originally approved in 2005. Last previous edition approved in 20052010 asD709605.D7096 10. DOI: 10.1520/D7096-10.10.1520/D7096-16.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standar
14、dsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to
15、 adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.*A Summary of Changes section appears at the end of this standardCopyright
16、ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13. Terminology3.1 Definitions:3.1.1 area slice, narea under a chromatogram within a specified retention time interval.3.1.2 final boiling point (FBP), nthe point at which a cumulative volume count
17、 equal to 99.5 % of the total volume countsunder the chromatogram is obtained.3.1.3 initial boiling point (IBP), nthe point at which a cumulative volume count equal to 0.5 % of the total volume countsunder the chromatogram is obtained.3.1.4 relative volume response factor (RVRF), nthe volume respons
18、e factor (see 3.1.8) of a component i relative to the volumeresponse factor of n-heptane.3.1.5 slice time, nthe retention time at the end of a given area slice.3.1.6 slice width, nthe fixed duration (1 s, or less) of the retention time intervals into which the chromatogram is divided. Itis determine
19、d from the reciprocal of the frequency used in the acquisition of data.3.1.7 volume count, nthe product of a slice area (or an area under a peak) and a volume response factor.3.1.8 volume response factor, na constant of proportionality that relates the area under a chromatogram to liquid volume.4. S
20、ummary of Test Method4.1 The sample is vaporized and transported by carrier gas into a non-polar, wide-bore capillary gas chromatographic column.The column temperature is raised at a reproducible, linear rate so as to elute the hydrocarbon components in boiling point orderfor measurement by a flame
21、ionization detector. Conditions are selected such that n-pentane and lighter saturated hydrocarbons inthe calibration mixture are resolved discretely. Linear correlation between hydrocarbon boiling point and retention time isestablished using a known mixture of hydrocarbons covering the boiling rang
22、e expected in the sample. Area slices are convertedto volume using theoretical hydrocarbon volume response factors. Oxygenated samples require experimental determination ofoxygenate response factors.5. Significance and Use5.1 The determination of the boiling range distribution of gasoline by gas chr
23、omatographic simulated distillation provides aninsight into the composition of the components from which the gasoline has been blended. Knowledge of the boiling rangedistribution of gasoline blending components is useful for the control of refinery processes and for the blending of finishedgasoline.
24、5.2 The determination of the boiling range distribution of light hydrocarbon mixtures by gas chromatographic simulateddistillation has better precision than the conventional distillation by Test Method D86.Additionally, this test method provides moreaccurate and detailed information about the compos
25、ition of the light ends. The distillation data produced by this test method aresimilar to that which would be obtained from a cryogenic, true boiling point (15 theoretical plates) distillation.5.3 This test method is intended to expand upon Test Method D3710 by defining mandatory response factors, u
26、se of capillarycolumn technology, inclusion of oxygenates, and use of flame ionization detection.6. Interferences6.1 Ethanol or other oxygenates may coelute with hydrocarbons present in the sample. Since the response of oxygenates issubstantially different from the response of hydrocarbons, response
27、 factors are used to correct the area slice for the elution intervalof oxygenates.6.2 Concentrations of n-pentane and lighter saturated compounds may be estimated from the analysis. However, early elutingolefins present in the gasoline samples may coelute with these compounds.6.3 For samples contain
28、ing ethanol, this test method will determine the hydrocarbon distribution. It will not simulate theazeotrope observed during physical distillation.7. Apparatus7.1 Gas ChromatographAny gas chromatograph (GC) designed for use with wide-bore (0.53 mm inside diameter) capillarycolumns, that meets the pe
29、rformance criteria specified in Section 11, and has the following features may be used. Typical operatingconditions are shown in Table 1.7.1.1 Column Oven Temperature ProgrammingThe gas chromatograph shall be capable of linear temperature-programmedoperation from 4040 C to 280C280 C at rates up to 2
30、5C/min.25 Cmin.7.1.2 Injection PortThe injection port shall be capable of operation at temperatures required to completely volatize andtransfer the sample to the GC column. Non-splitting or split/splitless vaporizing sample ports optimized for use with wide-borecapillary columns are acceptable. If u
31、sing a split inlet port, it should be designed to provide a linear sample split injection.D7096 1627.1.3 Flame Ionization DetectorThe detector shall be optimized for the use of wide-bore capillary gas chromatographiccolumns and shall conform to the specifications as described in Practice E594.7.1.4
32、Carrier Gas ControlsThe associated carrier gas controls shall be of sufficient precision to produce reproducible columnflows in order to maintain analytical integrity.7.1.5 Baseline CorrectionThe gas chromatograph (or another component of the gas chromatographic system) shall be capableof subtractin
33、g the area slice of a blank run from the corresponding area slice of a sample run. This can be done internally on somegas chromatographs (baseline compensation) or externally by subtracting a stored, digitized signal from a blank run.7.2 Sample IntroductionSample introduction may be by means of a co
34、nstant volume liquid sample valve or by injection witha micro syringe through a septum. An automatic sample introduction device is essential to the reproducibility of the analysis.Manual injections are not recommended. Poor injection technique can result in poor resolution. If column overload occurs
35、, peakskewing may result, leading to variation in retention times.7.2.1 Samples with a vapor pressure (VP) of less than 16 psia 16 psia as measured by Test Method D5191, or equivalent, maybe introduced into the gas chromatograph by syringe injection into a heated, vaporizing inlet. Samples with vapo
36、r pressuresTABLE 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 15Auxiliary flow (mL/min) 10 10Col
37、umn 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 syringeinjectionauto syringeinjectionInjector temperature (C) 250 250Detector temperature (C) 280
38、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 0.2Data rate (Hz) 2 5 2 5TABLE 2 Typical Operating Conditions for Capillary Column InletColumn length (m) 30Column I.D. (mm) 0.53Stationary phase 100 %polydimethylsiloxaneFilm thicknes
39、s 5 mCarrier gas helium (ramped flow)Carrier flow (mL/min) 5mL/min (0.5 min) to20mL/min 60mL/minCarrier flow (mL/min) 5 mL min (0.5 min) to20 mL min 60 mL minColumn initial temperature (C) 40Initial time (min) 1Program rate (C/min) 25Final temperature (C) 245Final hold (min) 4Injection port splitSam
40、ple introduction automatic syringeinjectionInjector temperature (C) 250Detector temperature (C) 250Hydrogen flow (mL/min) 30Air flow (mL/min) 300Sample size (L) 1 uLSplit ratio 1:50Data rate 5 HzD7096 163between 1212 psia and 16 psia should be kept chilled (refrigerated or in a cooled sample tray) a
41、nd may require injection with acooled syringe. Samples with a vapor pressure above 16 psia 16 psia should 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) column, coated with
42、 a non-polar (100 %polydimethylsiloxane) phase that meets the performance criteria of 11.3 may be used. Columns of 1515 metre to 30 metre 30 metrelengths with a stationary phase film thickness of 5.0 m 5.0 m have been successfully used. With either of these columns, initialcryogenic temperatures are
43、 not necessary.7.4 Data Acquisition SystemA computer provided with a monitor, printer, and data acquisition software is necessary to carryout this analysis. The computer should have sufficient hardware capacity and random access memory in order to run the dataacquisition program while acquiring data
44、 at a frequency of 22 Hz to 5 Hz. The software should also be able to store the data forfuture recall, inspection, and analysis. The data acquisition software should be capable of presenting a real time plot. It may alsobe capable of controlling the operating variables of the gas chromatograph. Spec
45、ialized software is necessary to obtain the boilingpoint distribution.7.5 Bulk Sample Containers, floating piston cylinders (see 9.1.1); epoxy phenolic-lined metal cans; glass bottles withpolytetrafluoroethylene-lined screw caps.8. Reagents and Materials8.1 Calibration MixtureAsynthetic mixture of p
46、ure liquid hydrocarbons with boiling points that encompass the boiling rangeof the sample shall be used for retention time determination and response factor validation. Response factors for propane,isobutane, and n-butane are extrapolated from the relative molar response of the n-paraffins. An examp
47、le of a relative responsefactor mixture with suggested nominal composition is given in Table 3. This mixture shall be accurately prepared on a mass basisusing Practice D4307 or equivalent.8.1.1 A single calibration standard may be used for retention time-boiling point determination and response fact
48、or validationprovided isopentane and heavier components are known quantitatively. Gaseous components propane, isobutane, and n-butane areadded in small quantities (P) according to 6.4.3 (Note 1) of Practice D6300, recommended “ furtherstandardization of the test method may be necessary.”3 Supporting
49、 data have been filed at ASTM International Headquarters and may be obtained by requesting Research Report RR:D02-1682.TABLE 6 Boling Point Ranges Covered in the Precision StudyAverage BP Low Range High RangeC F C F C FIBP -4.9 23.18 -12 10.4 2.3 36.1IBP 4.9 23.18 12 10.4 2.3 36.15 29.8 85.64 -0.4 31.28 60 140.05 29.8 85.64 0.4 31.28 60 140.010 41.6 106.88 3.1 37.58 80 176.020 59 138.2 27 80.6 91 195.830 75.5 167.9 41 105.8 110 230.040 87.5 189.5 64 147.2 111 231.850 109.5 229.1 81 177.8 138 280.460 124 255.
