1、Designation: D6730 01 (Reapproved 2011)Standard 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 D6730; the number immediately following th
2、e 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
3、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. Otherlight liquid hydrocarbon mixtures typically encountered inpetroleum refining operations, such as
4、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 study results, individual com-ponent concentrations and precision are determined in therange from 0.0
5、1 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 components withconcentrations outside the specified ranges.1.3 This test method also determines met
6、hanol, 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 cooperative study data provided insufficientstatistical data for obtaining a precision statement
7、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 group-type composition (PONA), the user of suchdata should be cautioned that some error will be enc
8、ountereddue 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 significant errors in PONA-type groupings. Basedon the gasoline samples in the interlaboratory co
9、operativestudy, 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 components or their higher boiling cuts such as thosederived from fluid catalytic cracking (FCC) are
10、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 group types for several interlaboratory cooperative studysamples. Although benzene, toulene, and
11、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.1.4.1 Total olefins in the samples may be obtained orconfirmed, or both, if necessary, by Test Meth
12、od D1319(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 desired, by the use of TestMethod D1744 or equivalent. Other compounds containingoxygen, sulfur, nitrog
13、en, 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 used, such as TestMethods D4815 and D5599 for oxygenates, and Test MethodD5623 for sulfur compound
14、s, or equivalent.1.6 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.7 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
15、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:2D1319 Test Method for Hydrocarbon Types in Liquid1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Prod
16、ucts and Lubricants and is the direct responsibility of SubcommitteeD02.04.0L on Gas Chromatography Methods.Current edition approved May 1, 2011. Published May 2011. Originallyapproved in 2001. Last previous edition approved in 2006 as D6730 01(2006)1.DOI: 10.1520/D6730-01R11.2For referenced ASTM st
17、andards, 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.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken
18、, PA 19428-2959, United States.Petroleum Products by Fluorescent Indicator AdsorptionD1744 Test Method for Determination of Water in LiquidPetroleum Products by Karl Fischer Reagent3D3700 Practice for Obtaining LPG Samples Using a Float-ing Piston CylinderD4057 Practice for Manual Sampling of Petrol
19、eum andPetroleum ProductsD4177 Practice for Automatic Sampling of Petroleum andPetroleum ProductsD4307 Practice for Preparation of Liquid Blends for Use asAnalytical StandardsD4626 Practice for Calculation of Gas ChromatographicResponse FactorsD4815 Test Method for Determination of MTBE, ETBE,TAME,
20、DIPE, tertiary-Amyl Alcohol and C1to C4Alco-hols in Gasoline by Gas ChromatographyD5580 Test Method for Determination of Benzene, Tolu-ene, Ethylbenzene, p/m-Xylene, o-Xylene, C9and HeavierAromatics, and Total Aromatics in Finished Gasoline byGas ChromatographyD5599 Test Method for Determination of
21、Oxygenates inGasoline by Gas Chromatography and Oxygen SelectiveFlame Ionization DetectionD5623 Test Method for Sulfur Compounds in Light Petro-leum Liquids by Gas Chromatography and Sulfur Selec-tive DetectionE355 Practice for Gas Chromatography Terms and Rela-tionshipsE594 Practice for Testing Fla
22、me Ionization Detectors Usedin Gas or Supercritical Fluid ChromatographyE1510 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.
23、 Detailed definitions can be found in Practice E355.4. 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. Heliu
24、m carrier gastransports 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 a
25、n integrator orintegrating 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 corre
26、ction with detectorresponse 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
27、 and product specification 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 metho
28、d,were developed to provide 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 wherethes
29、e are of two different 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 c
30、omposi-tion (PONA), the 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 error
31、s in PONA-typegroupings.5.4 If water is or is suspected of being present, its concen-tration is determined by the use of Test Method D1744. Othercompounds containing oxygen, sulfur, nitrogen, and so forthmay also be present, and may co-elute with the hydrocarbons.When known co-elution exists, these
32、are noted in the testmethod 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 D4815and D5599 for oxygenates, Test Method D5580 for aromatics,and Test Method D5623 for sulfur compounds.6
33、. Apparatus6.1 Gas 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-tu
34、re program followed by an isothermal temperature hold andanother programmed temperature rise. A heated flash vaporiz-ing injector designed to provide a linear sample split injection3Withdrawn. The last approved version of this historical standard is referencedon www.astm.org.4Johansen, N.G., and Ett
35、re, L.S., “Retention Index Values of Hydrocarbons onOpen Tubular Columns Coated with Methyl Silicone 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 Distillat
36、es. Part 1,”Journal of Chromatography, 256, 1983, pp. 393-417.6Kopp, V.R., Bones, C.J., Doerr, D.G., 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
37、. and Johansen, N.J., “Cooperative Study to Evaluate a StandardTest Method for the Speciation of Gasolines by Capillary Gas Chromatography,”SAE Paper No. 930144, March 1993.D6730 01 (2011)2(that is, 200:1) is required for proper sample introduction. Theassociated carrier gas controls must be of suff
38、icient precision toprovide reproducible column flows and split ratios in order tomaintain analytical 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
39、 in Practice E594, as wellas having an operating temperature range of up to at least250C.6.2 Sample 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 o
40、f 0.1 to 0.5L. injections are suitable. It should be noted that somesyringes and improper injection 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
41、 used for quantitating these analyses shall meet or exceedthese minimum requirements:6.3.1 Capacity 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
42、 or greater sampling rate).6.3.5 Maintain peak detection sensitivity for narrow andbroad peaks.6.3.6 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 Colu
43、mnThe column used for this testmethod consists of a primary (100 m) analytical column and aprecolumn. 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 ava
44、ilable columns. Some older col-umns, and columns that have a sample residue from repeateduse without 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 specif
45、ications. See Section 11 fora description of the column performance specifications andAnnex A1 for 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
46、diameter 0.25 mmLiquid phase methyl siliconeFilm thickness 0.50 mTheoretical plates, n, pentane 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 L
47、injector temperature: 300C sample: 0.2 L, 0.5 L, 1.0 L10.3 Compare the calculated concentrations 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 kno
48、wn!/concentration known (2)10.4 Report and use only those combinations of conditionsfrom 10.2 that 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 de
49、termined fornew column acceptability and are useful for periodic evalua-tion of column deterioration. 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 a
