1、Designation: D6839 16D6839 17Standard Test Method forHydrocarbon Types, Oxygenated Compounds, and Benzenein Spark Ignition Engine Fuels by Gas Chromatography1This standard is issued under the fixed designation D6839; the number immediately following the designation indicates the year oforiginal adop
2、tion 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.NOTEPreviously balloted and approved material was included and the year date changed
3、 on April 20, 2016.1. Scope*1.1 This test method covers the quantitative determination of saturates, olefins, aromatics, and oxygenates in spark-ignitionengine fuels by multidimensional gas chromatography. Each hydrocarbon type can be reported either by carbon number (see Note1) or as a total.NOTE 1
4、There can be an overlap between the C9 and C10 aromatics; however, the total is accurate. Isopropyl benzene is resolved from the C8 aromaticsand is included with the other C9 aromatics.1.2 This test method is not intended to determine individual hydrocarbon components except benzene.1.3 This test me
5、thod is divided into two parts, Part A and Part B.1.3.1 PartAis applicable to automotive motor gasoline for which precision (Table 9) has been obtained for total volume fractionof aromatics of up to 50 %; a total volume fraction of olefins from about 1.5 % up to 30 %; a volume fraction of oxygenates
6、, from0.8 % up to 15 %; a total mass fraction of oxygen from about 1.5 % to about 3.7 %; and a volume fraction of benzene of up to2 %. Although this test method can be used to determine higher-olefin contents of up to 50 % volume fraction, the precision forolefins was tested only in the range from a
7、bout 1.5 % volume fraction to about 30 % volume fraction. The method has also beentested for an ether content up to 22 % volume fraction but no precision data has been determined.1.3.1.1 This test method is specifically developed for the analysis of automotive motor gasoline that contains oxygenates
8、, butit also applies to other hydrocarbon streams having similar boiling ranges, such as naphthas and reformates.1.3.2 Part B describes the procedure for the analysis of oxygenated groups (ethanol, methanol, ethers, C3 to C5 alcohols) inethanol fuels containing an ethanol volume fraction between 50
9、% and 85 % (17 % to 29 % oxygen). The gasoline is diluted withan oxygenate-free component to lower the ethanol content to a value below 20 % before the analysis by GC. The diluting solventshould not be considered in the integration, this makes it possible to report the results of the undiluted sampl
10、e after normalizationto 100 %.1.4 Oxygenates as specified inTest Method D4815 have been verified not to interfere with hydrocarbons.Within the round robinsample set, the following oxygenates have been tested: MTBE, ethanol, ETBE, TAME, iso-propanol, isobutanol, tert-butanol andmethanol. The derived
11、precision data for methanol do not comply with the precision calculation as presented in this InternationalStandard. Applicability of this test method has also been verified for the determination of n-propanol, acetone, and di-isopropylether (DIPE). However, no precision data have been determined fo
12、r these compounds.1.4.1 Other oxygenates can be determined and quantified using Test Method D4815 or D5599.1.5 The method is harmonized with ISO 22854.1.6 This test method includes a relative bias section for U.S. EPA spark-ignition engine fuel regulations for total olefinsreporting based on Practic
13、e D6708 accuracy assessment between Test Method D6839 and Test Method D1319 as a possible TestMethod D6839 alternative to Test Method D1319. The Practice D6708 derived correlation equation is only applicable for fuels inthe total olefins concentration range from 0.2 % to 18.2 % by volume as measured
14、 by Test Method D6839. The applicable TestMethod D1319 range for total olefins is from 0.6 % to 20.6 % by volume as reported by Test Method D1319.1.7 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1 This test method is under
15、the jurisdiction ofASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of SubcommitteeD02.04.0L on Gas Chromatography Methods.Current edition approved April 20, 2016June 1, 2017. Published April 2016June 2017. Originally approved in 2002. Last prev
16、ious edition approved in 20152016 asD6839 15.D6839 16. DOI: 10.1520/D6839-16.10.1520/D6839-17.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 poss
17、ible to 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 standardCop
18、yright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States11.8 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 to establish appropriate safe
19、ty and health practices and determine the applicability of regulatorylimitations prior to use.1.9 This international standard was developed in accordance with internationally recognized principles on standardizationestablished in the Decision on Principles for the Development of International Standa
20、rds, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D1319 Test Method for Hydrocarbon Types in Liquid Petroleum Products by Fluorescent Indicator AdsorptionD4307 Practice for Preparation of Liqui
21、d Blends for Use as Analytical StandardsD4815 Test Method for Determination of MTBE, ETBE, TAME, DIPE, tertiary-Amyl Alcohol and C1 to C4 Alcohols inGasoline by Gas ChromatographyD5599 Test Method for Determination of Oxygenates in Gasoline by Gas Chromatography and Oxygen Selective FlameIonization
22、DetectionD6708 Practice for Statistical Assessment and Improvement of Expected Agreement Between Two Test Methods that Purportto Measure the Same Property of a Material2.2 Other Documents:ISO 4259 Petroleum ProductsDetermination and Application of Precision Data in Relation to Methods of Test3ISO 22
23、854 Liquid Petroleum ProductsDetermination of Hydrocarbon Types and Oxygenates in Automotive-MotorGasolineMultidimensional Gas Chromatography Method33. Terminology3.1 Definitions:3.1.1 oxygenate, nan oxygen-containing organic compound, which may be used as a fuel or fuel supplement, for example,vari
24、ous alcohols and ethers.3.2 Definitions of Terms Specific to This Standard:3.2.1 hydrogenation, nthe process of adding hydrogen to olefin molecules as a result of a catalytic reaction.3.2.1.1 DiscussionHydrogenation is accomplished when olefins in the sample contact platinum at a temperature of 180
25、C in the presence ofhydrogen. The olefins are converted into hydrogen saturated compounds of the same carbon number and structure. Monoolefinsand diolefins convert to paraffins while cycloolefins and cyclodienes convert to cycloparaffins.3.2.2 trap, na device utilized to selectively retain specific
26、portions (individual or groups of hydrocarbons or oxygenates) ofthe test sample and to release the retained components by changing the trap temperature.3.3 Acronyms:3.3.1 ETBEethyl-tert-butylether3.3.2 MTBEmethyl-tert-butylether3.3.3 TAMEtert-amyl-methylether3.3.4 DIPEdi-isopropylether4. Summary of
27、Test Method4.1 A representative sample is introduced into a computer controlled gas chromatographic system consisting of switchingvalves, columns, and an olefin hydrogenation catalyst, all operating at various temperatures. The valves are actuated atpredetermined times to direct portions of the samp
28、le to appropriate columns and traps. As the analysis proceeds, the columnsseparate these sample portions sequentially into groups of different hydrocarbon types that elute to a flame ionization detector.4.2 The mass concentration of each detected compound or hydrocarbon group is determined by the ap
29、plication of responsefactors to the areas of the detected peaks followed by normalization to 100 %. For samples containing methanol or otheroxygenates that cannot be determined by this test method, the hydrocarbon results are normalized to 100 % minus the value of theoxygenates as determined by anot
30、her test method such as Test Method D4815 or D5599.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3 Availabl
31、e from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http:/www.ansi.org.D6839 1724.3 The liquid volume concentration of each detected compound or hydrocarbon group is determined by application of densityfactors to the calculated mass concentration of th
32、e detected peaks followed by normalization to 100 %.5. Significance and Use5.1 A knowledge of spark-ignition engine fuel composition is useful for regulatory compliance, process control, and qualityassurance.5.2 The quantitative determination of olefins and other hydrocarbon types in spark-ignition
33、engine fuels is required to complywith government regulations.5.3 This test method is not applicable to M85 fuels, which contain 85 % methanol.6. Interferences6.1 Some types of sulfur-containing compounds are irreversibly adsorbed in the olefin trap reducing its capacity to retain olefins.Sulfur con
34、taining compounds are also adsorbed in the alcohol and ether-alcohol-aromatic (EAA) traps. However, a variety ofspark-ignition engine fuels have been analyzed without significant performance deterioration of these traps.6.2 Commercial dyes used to distinguish between grades and types of spark-igniti
35、on engine fuels have been found not tointerfere with this test method.6.3 Commercial detergent additives utilized in spark-ignition engine fuels have been found not to interfere with this test method.6.4 Dissolved water in spark-ignition engine fuels has been found not to interfere with this test me
36、thod.7. Apparatus7.1 The complete system that was used to obtain the precision data shown in Section 14 is comprised of a computer controlledgas chromatograph, automated sample injector, and specific hardware modifications. These modifications include columns, traps,a hydrogenator, and valves, which
37、 are described in 7.7 and in Section 8. Fig. 1 illustrates a typical instrument configuration (seeFIG. 1 Typical Instrument ConfigurationD6839 173Note 4). Other configurations, components, or conditions may be utilized provided they are capable of achieving the requiredcomponent separations and prod
38、uce a precision that is equivalent to, or better than, that shown in the precision tables.7.2 Gas Chromatograph, capable of temperature programmed operation at specified temperatures, equipped with a heated flashvaporization inlet, a flame ionization detector, necessary flow controllers, and compute
39、r control.7.3 Sample Introduction System, using an automatic liquid injector, the injection volume shall be chosen in a way such that thecapacity of the column is not exceeded and that the linearity of the detector is valid.7.3.1 An injection volume of 0.1 L has been found satisfactory.7.4 Gas Flow
40、and Pressure Controllers, with adequate precision to provide reproducible flow and pressure of the carrier gasto the chromatographic system, hydrogen for the hydrogenator, and hydrogen and air for the flame ionization detector. Control ofair flow for cooling specific system components and for automa
41、ted valve operation is also required.7.5 Electronic Data Acquisition System, shall meet or exceed the following specifications (see Note 2):7.5.1 Capacity for 150 peaks for each analysis.7.5.2 Normalized area percent calculation with response factors.7.5.2.1 Area summation of peaks that are split or
42、 of groups of components that elute at specific retention times.7.5.3 Noise and spike rejection capability.7.5.4 Sampling rate for fast (20 Hz to give 10 points across peak).7.5.5 Peak width detection for narrow and broad peaks.7.5.6 Perpendicular drop and tangent skimming, as required.NOTE 2Standar
43、d supplied software is typically satisfactory.7.6 Temperature Controllers of System ComponentsThe independent temperature control of numerous columns and traps, thehydrogenation catalyst, column switching valves, and sample lines is required. All of the system components that contact thesample shall
44、 be heated to a temperature that will prevent condensation of any sample component. Table 1 lists the systemcomponents and operating temperatures (see 7.6.1). Some of the components require isothermal operation, some require rapidheating and cooling, while one requires reproducible temperature progr
45、amming. The indicated temperatures are typical; however,the control systems utilized shall have the capability of operating at temperatures 620 C of those indicated to accommodatespecific systems. Temperature control may be by any means that will meet the requirements listed in Table 1.7.6.1 The sys
46、tem components and temperatures listed in Table 1 and Section 8 are specific to the analyzer used to obtain theprecision data shown in Section 14. Other columns and traps that can adequately perform the required separations are alsosatisfactory but may require different temperatures.7.7 Valves, Colu
47、mn and Trap SwitchingSuitable automated switching valves are recommended. The valves shall be intendedfor gas chromatographic usage and meet the following requirements:7.7.1 The valves must be capable of continuous operation at operating temperatures that will prevent sample condensation.7.7.2 The v
48、alves shall be constructed of materials that are nonreactive with the sample under analysis conditions. Stainless steel,PFA, and Vespel4 are satisfactory.7.7.3 The valves shall have a small internal volume but offer little restriction to carrier gas flow under analysis conditions.7.7.4 New valves, t
49、ubing, catalyst, columns, traps, and other materials that contact the sample or gasses may requireconditioning prior to operation in accordance with the manufacturers recommendations.7.8 Gas Purifiers, to remove moisture and oxygen from helium, moisture and hydrocarbons from hydrogen, and moisture andhydrocarbons from air.4 PFA and Vespel are trademarks of E. I. DuPont de Nemours and Co.TABLE 1 Temperature Control Ranges of System ComponentsComponentTypicalOperatingTemperatureRange, CMaximumHeatingTime, minMaximumCoolingTime, minAlcohol trap 60280 2 5Pol
