1、Designation: D 6730 01 (Reapproved 2006)e1An American National StandardStandard Test Method forDetermination of Individual Components in Spark IgnitionEngine Fuels by 100Metre Capillary (with Precolumn) High-Resolution Gas Chromatography1This standard is issued under the fixed designation D 6730; th
2、e 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 (e) indicates an editorial change since the last revision or reapproval.e1
3、NOTECorrected Referenced Documents editorially in April 2007.1. Scope1.1 This test method covers the determination of individualhydrocarbon components of spark-ignition engine fuels andtheir mixtures containing oxygenate blends (MTBE, ETBE,ethanol, and so forth) with boiling ranges up to 225C. Other
4、light liquid hydrocarbon mixtures typically encountered inpetroleum refining operations, such as blending stocks (naph-thas, reformates, alkylates, and so forth) may also be analyzed;however, statistical data was obtained only with blendedspark-ignition engine fuels.1.2 Based on the cooperative stud
5、y results, individual com-ponent concentrations and precision are determined in therange from 0.01 to approximately 30 mass %. The test methodmay be applicable to higher and lower concentrations for theindividual components; however, the user must verify theaccuracy if the test method is used for co
6、mponents withconcentrations outside the specified ranges.1.3 This test method also determines methanol, ethanol,t-butanol, methyl t-butyl ether (MTBE), ethyl t-butyl ether(ETBE), and t-amyl methyl ether (TAME) in spark ignitionengine fuels in the concentration range from 1 to 30 mass %.However, the
7、cooperative study data provided insufficientstatistical data for obtaining a precision statement for thesecompounds.1.4 Although a majority of the individual hydrocarbonspresent are determined, some co-elution of compounds isencountered. If this test method is utilized to estimate bulkhydrocarbon gr
8、oup-type composition (PONA), the user of suchdata should be cautioned that some error will be encountereddue to co-elution and a lack of identification of all componentspresent. Samples containing significant amounts of naphthenic(for example, virgin naphthas) constituents above n-octanemay reflect
9、significant errors in PONA-type groupings. Basedon the gasoline samples in the interlaboratory cooperativestudy, this test method is applicable to samples containing lessthan 25 mass % of olefins. However, some interfering co-elution with the olefins above C7is possible, particularly ifblending comp
10、onents or their higher boiling cuts such as thosederived from fluid catalytic cracking (FCC) are analyzed, andthe total olefin content may not be accurate. Annex A1 of thistest method compares results of the test method with other testmethods for selected components, including olefins, and sev-eral
11、group types for several interlaboratory cooperative studysamples. Although benzene, toulene, and several oxygenatesare determined, when doubtful as to the analytical results ofthese components, confirmatory analyses can be obtained byusing the specific test methods listed in the reference section.1.
12、4.1 Total olefins in the samples may be obtained orconfirmed, or both, if necessary, by Test Method D 1319(volume %) or other test methods, such as those based onmultidimentional PONA-type of instruments.1.5 If water is or is suspected of being present, its concen-tration may be determined, if desir
13、ed, by the use of TestMethod D 1744 or equivalent. Other compounds containingoxygen, sulfur, nitrogen, and so forth, may also be present, andmay co-elute with the hydrocarbons. If determination of thesespecific compounds is required, it is recommended that testmethods for these specific materials be
14、 used, such as TestMethods D 4815 and D 5599 for oxygenates, and Test MethodD 5623 for sulfur compounds, or equivalent.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-pri
15、ate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 1319 Test Method for Hydrocarbon Types in Liquid1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants a
16、nd is the direct responsibility of SubcommitteeD02.04.0L on Gas Chromatography Methods.Current edition approved Nov. 1, 2006. Published January 2007. Originallyapproved in 2001. Last previous edition approved in 2001 as D 6730 01.2For referenced ASTM standards, visit the ASTM website, www.astm.org,
17、orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.Petroleum Produc
18、ts by Fluorescent Indicator AdsorptionD 1744 Test Method for Determination of Water in LiquidPetroleum Products by Fluorescent Indicator Adsorption3D 3700 Practice for Obtaining LPG Samples Using a Float-ing Piston CylinderD 4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD 4177
19、Practice for Automatic Sampling of Petroleum andPetroleum ProductsD 4307 Practice for Preparation of Liquid Blends for Use asAnalytical StandardsD 4626 Practice for Calculation of Gas ChromatographicResponse FactorsD 4815 Test Method for Determination of MTBE, ETBE,TAME, DIPE, tertiary-Amyl Alcohol
20、and C1to C4Alco-hols in Gasoline by Gas ChromatographyD 5580 Test Method for Determination of Benzene, Tolu-ene, Ethylbenzene, p/m-Xylene, o-Xylene, C9and HeavierAromatics, and Total Aromatics in Finished Gasoline byGas ChromatographyD 5599 Test Method for Determination of Oxygenates inGasoline by G
21、as Chromatography and Oxygen SelectiveFlame Ionization DetectionD 5623 Test Method for Sulfur Compounds in Light Petro-leum Liquids by Gas Chromatography and Sulfur Selec-tive DetectionE 355 Practice for Gas Chromatography Terms and Rela-tionshipsE 594 Practice for Testing Flame Ionization Detectors
22、 Usedin Gas or Supercritical Fluid ChromatographyE 1510 Practice for Installing Fused Silica Open TubularCapillary Columns in Gas Chromatographs3. Terminology3.1 DefinitionsThis test method makes reference to manycommon gas chromatographic procedures, terms, and relation-ships. Detailed definitions
23、can be found in Practice E 355.4. Summary of Test Method4.1 A representative sample of the petroleum liquid isintroduced into a gas chromatograph equipped with an opentubular (capillary) column coated with a methyl silicone liquidphase, modified with a capillary precolumn. Helium carrier gastranspor
24、ts the vaporized sample through the column, in whichit is partitioned into individual components which are sensedwith a flame ionization detector as they elute from the end ofthe column. The detector signal is presented on a strip chartrecorder or digitally, or both, by way of an integrator orintegr
25、ating computer. Each eluting component is identified bycomparing its retention time to that established by analyzingreference standards or samples under identical conditions. Theconcentration of each component in mass % is determined bynormalization of the peak areas after correction with detectorre
26、sponse factors. Unknown components are reported as a totalunknown mass %.5. Significance and Use5.1 Knowledge of the individual component composition(speciation) of gasoline fuels and blending stocks is useful forrefinery quality control and product specification. Processcontrol and product specific
27、ation compliance for many indi-vidual hydrocarbons can be determined through the use of thistest method.5.2 This test method is adopted from earlier developmentand enhancement.4,5,6,7The chromatographic operating condi-tions and column tuning process, included in this test method,were developed to p
28、rovide and enhance the separation andsubsequent determination of many individual components notobtained with previous single-column analyses. The columntemperature program profile is selected to afford the maximumresolution of possible co-eluting components, especially wherethese are of two differen
29、t compound types (for example, aparaffin and a naphthene).5.3 Although a majority of the individual hydrocarbonspresent in petroleum distillates are determined, some co-elution of compounds is encountered. If this test method isutilized to determine bulk hydrocarbon group-type composi-tion (PONA), t
30、he user of such data should be cautioned thatsome error will be encountered due to co-elution and a lack ofidentification of all components present. Samples containingsignificant amounts of olefinic or naphthenic, or both, constitu-ents above octane may reflect significant errors in PONA-typegroupin
31、gs.5.4 If water is or is suspected of being present, its concen-tration is determined by the use of Test Method D 1744. Othercompounds containing oxygen, sulfur, nitrogen, and so forthmay also be present, and may co-elute with the hydrocarbons.When known co-elution exists, these are noted in the tes
32、tmethod data tables. If determination of these specific com-pounds is required, it is recommended that test methods forthese specific materials be used, such as Test Method D 4815and D 5599 for oxygenates, Test Method D 5580 for aromatics,and Test Method D 5623 for sulfur compounds.6. Apparatus6.1 G
33、as ChromatographInstrumentation capable of col-umn oven temperature programming, from subambient (5C)to at least 200C, in 0.1C/min or less rate increments, isrequired. Multi-step column oven temperature programming isrequired, consisting of an initial hold time, an initial tempera-ture program follo
34、wed by an isothermal temperature hold andanother programmed temperature rise. A heated flash vaporiz-ing injector designed to provide a linear sample split injection3Withdrawn.4Johansen, N.G., and Ettre, L.S., “Retention Index Values of Hydrocarbons onOpen Tubular Columns Coated with Methyl Silicone
35、 Liquid Phases,” Chro-matographia, Vol 5, No. 10, October 1982.5Johansen, N.G., Ettre, L.S., and Miller, R.L., “Quantitative Analysis ofHydrocarbons by Structural Group Type in Gasolines and Distillates. Part 1,”Journal of Chromatography, 256, 1983, pp. 393-417.6Kopp, V.R., Bones, C.J., Doerr, D.G.,
36、 Ho, S.P., and Schubert, A.J., “HeavyHydrocarbon/Volatility Study: Fuel Blending and Analysis for the Auto/Oil AirQuality Improvement Research Program,” SAE Paper No. 930143, March 1993.7Schubert, A.J. and Johansen, N.J., “Cooperative Study to Evaluate a StandardTest Method for the Speciation of Gas
37、olines by Capillary Gas Chromatography,”SAE Paper No. 930144, March 1993.D 6730 01 (2006)e12(that is, 200:1) is required for proper sample introduction. Theassociated carrier gas controls must be of sufficient precision toprovide reproducible column flows and split ratios in order tomaintain analyti
38、cal integrity. A hydrogen flame ionizationdetector, with associated gas controls and electronics, designedfor optimum response with open tubular columns, shall con-form to the specifications as described in Practice E 594, aswell as having an operating temperature range of up to at least250C.6.2 Sam
39、ple IntroductionManual or automatic liquidsample injection to the splitting injector may be employed.Automated injections are highly recommended. Micro-syringes, auto-syringe samplers, or valves capable of 0.1 to 0.5L. injections are suitable. It should be noted that somesyringes and improper inject
40、ion techniques as well as inad-equate splitter design could result in sample fractionation. Thismust be determined in accordance with Section 10.6.3 Electronic IntegratorAny electronic integration de-vice used for quantitating these analyses shall meet or exceedthese minimum requirements:6.3.1 Capac
41、ity to handle 400 or more peaks per analysis.6.3.2 Normalized area percent calculation with responsefactors.6.3.3 Noise and spike rejection.6.3.4 Accurate area determination of fast (1 to 2 s) peaks (10Hz or greater sampling rate).6.3.5 Maintain peak detection sensitivity for narrow andbroad peaks.6
42、.3.6 Positive and negative sloping baseline correction.6.3.7 Perpendicular drop and tangent skimming as needed.6.3.8 Display of baseline used to ensure correct peak areadetermination.6.4 Open Tubular ColumnThe column used for this testmethod consists of a primary (100 m) analytical column and apreco
43、lumn. The ability to provide the required componentseparations is dependent on the precise control of the columnselectivity, which is typically slightly more than that exhibitedby current commercially available columns. Some older col-umns, and columns that have a sample residue from repeateduse wit
44、hout conditioning, may exhibit the required polarity.Until adequate columns are commercially available, the cur-rently used methyl silicone columns can be modified or tunedto meet the method column specifications. See Section 11 fora description of the column performance specifications andAnnex A1 f
45、or a description of the column modificationprocedure.6.4.1 The primary gas chromatographic column used forthis test method will meet the following specifications.Material fused silicaLength 100 mInternal diameter 0.25 mmLiquid phase methyl siliconeFilm thickness 0.50 mTheoretical plates, n, pentane
46、at 35C ; 400 000 to 500 000Retention factor, k, pentane at 35C 0.45 to 0.50Resolution, R, t-butanol and 2-methylbutene-2 at35C3.25 to 5.25Peak symmetry, t-butanol at 35C 1.0 to sample: 0.2 L, 0.5 L, 1.0 Linjector temperature: 300C sample: 0.2 L, 0.5 L, 1.0 L10.3 Compare the calculated concentrations
47、 to the knownstandard concentrations after calculating the corrected areanormalization using the response factors from 13.2 andTable A1.1.% relative error 5100 3concentration determined2 concentration known!/concentration known (2)10.4 Report and use only those combinations of conditionsfrom 10.2 th
48、at result in 3 % or less relative error. This is thesplitter linearity range.11. Column Evaluation11.1 In order to establish that a column will perform asrequired, the following specifications shall be determined fornew column acceptability and are useful for periodic evalua-tion of column deteriora
49、tion. These specification determina-tions can be made with or without a precolumn, since theprecolumn will have little effect on their values. SeeAnnexA1,Fig.A1.1, for examples of these determinations.After perform-ing the steps in Sections 9 and 10, analyze the columnperformance mixture (7.5.5) at 35C isothermal, at leastthrough heptane. The remainder of the analysis may beignored, but the remaining components must be eluted from thecolumn prior to performing another analysis. Setting thecolumn temperature to 220C for an additional 20 min will besufficien
