1、Designation: D6733 01 (Reapproved 2016)Standard Test Method forDetermination of Individual Components in Spark IgnitionEngine Fuels by 50-Metre Capillary High Resolution GasChromatography1This standard is issued under the fixed designation D6733; the number immediately following the designation indi
2、cates 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 the determination
3、of individualhydrocarbon components of spark-ignition engine fuels withboiling ranges up to 225 C. Other light liquid hydrocarbonmixtures typically encountered in petroleum refiningoperations, such as, blending stocks (naphthas, reformates,alkylates, and so forth) may also be analyzed; however,stati
4、stical data was obtained only with blended spark-ignitionengine fuels. The tables in Annex A1 enumerate the compo-nents reported. Component concentrations are determined inthe range from 0.10 % to 15 % by mass. The procedure may beapplicable to higher and lower concentrations for the individualcompo
5、nents; however, the user must verify the accuracy if theprocedures are used for components with concentrations out-side the specified ranges.1.2 This test method is applicable also to spark-ignitionengine fuel blends containing oxygenated components.However, in this case, the oxygenate content must
6、be deter-mined by Test Methods D5599 or D4815.1.3 Benzene co-elutes with 1-methylcyclopentene. Benzenecontent must be determined by Test Method D3606 or D5580.1.4 Toluene co-elutes with 2,3,3-trimethylpentane. Toluenecontent must be determined by Test Method D3606 or D5580.1.5 Although a majority of
7、 the individual hydrocarbonspresent are determined, some co-elution of compounds isencountered. If this procedure is utilized to estimate bulkhydrocarbon group-type composition (PONA) the user of suchdata should be cautioned that error may be encountered due toco-elution and a lack of identification
8、 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 interlaboratory cooperative study, this procedure isapplicable to samples having concentrations
9、of olefins less than20 % by mass. However, significant interfering coelution withthe olefins above C7is possible, particularly if blendingcomponents or their higher boiling cuts such as those derivedfrom fluid catalytic cracking (FCC) are analyzed, and the totalolefin content may not be accurate. Ma
10、ny of the olefins in sparkignition fuels are at a concentration below 0.10 %; they are notreported by this test method and may bias the total olefinresults low.1.5.1 Total olefins in the samples may be obtained orconfirmed, or both, by Test Method D1319 (volume %) orother test methods, such as those
11、 based on multidimensionalPONA type of instruments.1.6 If water is or is suspected of being present, its concen-tration may be determined, if desired, by the use of TestMethod D1744. Other compounds containing sulfur, nitrogen,and so forth, may also be present, and may co-elute with thehydrocarbons.
12、 If determination of these specific compounds isrequired, it is recommended that test methods for these specificmaterials be used, such as Test Method D5623 for sulfurcompounds.1.7 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are provided forinform
13、ation only.1.8 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 safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. R
14、eferenced Documents2.1 ASTM Standards:2D1319 Test Method for Hydrocarbon Types in Liquid Petro-leum Products by Fluorescent Indicator AdsorptionD1744 Test Method for Determination of Water in Liquid1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products, Liquid Fuels,
15、and Lubricantsand is the direct responsibility ofSubcommittee D02.04.0L on Gas Chromatography Methods.Current edition approved April 1, 2016. Published June 2016. Originallyapproved in 2001. Last previous edition approved in 2011 as D6733 01 (2011).DOI: 10.1520/D6733-01R16.2For referenced ASTM stand
16、ards, 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.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA
17、 19428-2959. United States1Petroleum Products by Karl Fischer Reagent (Withdrawn2016)3D3606 Test Method for Determination of Benzene andToluene in Finished Motor and Aviation Gasoline by GasChromatographyD4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD4420 Test Method for Deter
18、mination of Aromatics inFinished Gasoline by Gas Chromatography (Withdrawn2004)3D4815 Test Method for Determination of MTBE, ETBE,TAME, DIPE, tertiary-Amyl Alcohol and C1to C4Alco-hols in Gasoline by Gas ChromatographyD5580 Test Method for Determination of Benzene, Toluene,Ethylbenzene, p/m-Xylene,
19、o-Xylene, C9and HeavierAromatics, and Total Aromatics in Finished Gasoline byGas ChromatographyD5599 Test Method for Determination of Oxygenates inGasoline by Gas Chromatography and Oxygen SelectiveFlame Ionization DetectionD5623 Test Method for Sulfur Compounds in Light Petro-leum Liquids by Gas Ch
20、romatography and Sulfur Selec-tive DetectionE355 Practice for Gas Chromatography Terms and Relation-ships3. Terminology3.1 DefinitionsThis test method makes reference to manycommon gas chromatographic procedures, terms, and relation-ships. Detailed definitions can be found in Practice E355.4. Summar
21、y of Test Method4.1 Representative samples of the petroleum liquid areintroduced into a gas chromatograph equipped with an opentubular (capillary) column coated with specified stationaryphase(s). Helium carrier gas transports the vaporized samplethrough the column in which it is partitioned into ind
22、ividualcomponents, which are sensed with a flame ionization detectoras they elute from the end of the column. The detector signalis recorded digitally by way of an integrator or integratingcomputer. Each eluting component is identified by comparingits retention time to those established by analyzing
23、 referencestandards or samples under identical conditions. The concen-tration of each component in mass % is determined by normal-ization of the peak areas after correction of selected compo-nents with detector response factors. The unknowncomponents are reported individually as well as a summarytot
24、al.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 specification compliance for many indi-vidual hydrocarbons may be determined t
25、hrough the use of thistest method.6. Apparatus6.1 InstrumentationA gas chromatograph capable of op-erating under the conditions outlined in Table 1, equipped witha split injector, a carrier gas pressure control, and a flameionization detector which are required.6.2 Sample Introduction SystemManual o
26、r automatic liq-uid syringe sample injection may be employed.6.3 Data Acquisition SystemAny data system can be usedwith a requirement:6.3.1 Sampling rate of 10 Hz or more with a storage ofsampling data for later processing.6.3.2 Capacity for at least 400 peaks/analysis.6.3.3 Identification of indivi
27、dual components from retentiontime; software can be used to automatically identify the peakswith the index system determined from Table A1.1 or TableA1.2.6.4 SamplingTwo millilitres or more crimp-top vials andaluminum caps with polytetrafluoroethylene (PTFE)-linedsepta are used to transfer the sampl
28、e.6.5 Capillary ColumnA 50 m fused silica capillary col-umn with an internal diameter of 0.2 mm, containing a 0.5 mfilm thickness of bonded dimethylpolysiloxane phase is used.The features must be respected to reproduce the separation ofthe reference chromatogram. The column must meet thecriteria of
29、efficiency, resolution, and polarity defined in Section10.7. Reagents and Materials7.1 Carrier Gas and Make-up, helium, 99.99 mol % pure.(WarningCompressed gas under high pressure.)7.2 Fuel Gas, hydrogen, hydrocarbon free, 99.99 mol %pure. (WarningCompressed gas under high pressure.Ex-tremely flamma
30、ble.)7.3 Oxidizing Gas, air, 99 mol %. (WarningCompressedgas under high pressure.)7.4 n-Pentane, 99+ mol % pure. (WarningExtremelyflammable. Harmful if inhaled.)7.5 n-Hexane, 99+ % mol % pure. (WarningExtremelyflammable. Harmful if inhaled.)3The last approved version of this historical standard is r
31、eferenced onwww.astm.org.TABLE 1 Operating ConditionsTemperatures Method 1 Method 2Column initial isotherm, C 35 10Initial hold time, min. 10 15Rate 1, C/min. 1.1 1.3Final temperature 1, C 114 70Hold time 2, min. 0 0Rate 2, C/min 1.7 1.7Final temperature 2, C 250 250Final hold time 2, min. 5 20Injec
32、tor, C 250 250Detector, C 280 280Carrier gas helium pressure, kPA (psi) 207 (30) 190 (27)Flow rate (initial isotherm), mL/min. 0.9 0.7Average linear velocity, cm/s 22 21.5InjectionSample size, L 0.5 0.3Splitter ventflow out, mL/min. 250 200D6733 01 (2016)27.6 n-Heptane, 99+ mol % pure. (WarningExtre
33、melyflammable. Harmful if inhaled.)7.7 2-Methylheptane, 99+ mol % pure. (WarningExtremely flammable. Harmful if inhaled.)7.8 4-Methylheptane, 99+ mol % pure. (WarningExtremely flammable. Harmful if inhaled.)7.9 n-Octane, 99+ mol % pure. (WarningExtremelyflammable. Harmful if inhaled.)7.10 n-Dodecane
34、, 99+ mol % pure. (WarningExtremelyflammable. Harmful if inhaled.)7.11 Toluene, 99+ mol % pure. (WarningExtremelyflammable. Harmful if inhaled.)7.12 System Performance MixtureWeigh an equal amountof n-pentane, n-heptane, n-octane, n-dodecane,2-methylheptane, 4-methylheptane, and toluene. Dilute this
35、mixture in n-hexane to obtain a concentration of 2 % by massfor each compound.8. Sampling8.1 Container SamplingSamples shall be taken as de-scribed in Practice D4057 for instructions on manual samplinginto open container.8.2 The sample and a 2 mL vial must be cooled at 4 C. Partof the sample is tran
36、sferred to the vial up to 80 % of its volume,and aluminum cap with septum is crimped.9. Preparation of Apparatus9.1 InstallationInstall and condition column in accor-dance with the suppliers instruction.9.2 Operating ConditionsTwo sets of operating condi-tions are proposed in Table 1, the first with
37、 an initial columntemperature above the ambient temperature, the second with asub-ambient column temperature profile. Adjust the operatingconditions of the gas chromatograph to conform to the first orsecond method.9.3 Carrier Gas PressureSet a correct carrier gas pressureusing the system performance
38、 mixture such that the retentiontime of n-Heptane, n-Octane and n-Dodecane are between thevalues given in Table 2.10. System Performance Evaluation10.1 Evaluation of the column and linearity of the splitinjection are carried out with a system performance mixturedefined in 7.12 and with the column te
39、mperature conditionsdefined in the following table.Initial temperature 35 CHold time 50 minFinal temperature 220 CHold time 20 minRate 3 C min.10.2 Column EvaluationTo perform the requiredseparation, the column must meet three criteria of separation:efficiency, resolution, and polarity.10.2.1 Effcie
40、ncyThe number of theoretical plates is cal-culated with the normal octane peak using Eq 1:n 5 5.545Rt/W0.5!2(1)where:n = number of theoretical plates,Rt = retention time of normal octane, andW0.5= mid-height peak width of normal octane in the sameunit as retention time.10.2.1.1 The number of theoret
41、ical plates must be greaterthan 200 000.10.2.2 ResolutionResolution is determined between thepeaks of 2-methylheptane and 4-methylheptane using Eq 2:R 52Rta!2 Rtb!1.699W0.5a!1W0.5b!(2)where:Rt(a)= retention time of 4-methylheptane,Rt(b)= retention time of 2-methylheptane,W0.5(a)= mid-height peak wid
42、th of 4-methylheptane in thesame unit as retention time, andW0.5(b)= mid-height peak width of 2-methylheptane in thesame unit as retention time.10.2.2.1 The resolution must be equal to 4 or greater than1.20.10.2.3 PolarityPolarity is defined by the McReynoldsconstant of toluene, using Eq 3:Rntol5 Ki
43、ana2 Kisqualane(3)where:Kisqualane= toluene Kovats index on Squalane at35 C = 742.6, andKiana= toluene Kovats index on the analytical column at35 C.10.2.3.1 Toluene Kovats index is calculated using Eq 4:Kiana5 7001100SlogTRt!2 logTRh!logTRo!2 logTRh!D(4)where:TR(t)= adjusted retention time for tolue
44、ne,TR(h)= adjusted retention time for n-heptane, andTR(o)= adjusted retention time for n-octane.10.2.3.2 Adjusted retention time of a peak is determined bysubtracting the retention time of an unretained compound (airor methane) from the retention time of the peak. The McReyn-olds constant must be le
45、ss than 10.10.2.4 Base Line StabilityBase line stability is calculatedwith the difference between area slices at the beginning and atTABLE 2 Reference Retention Times of Normal ParaffinsNOTE 1Minutes and tenths of a minute.Method1Method1Method1Method2Method2Method2n-Paraffins LowerTimeRefer-enceTime
46、UpperTimeLowerTimeRefer-enceTimeUpperTimen-Heptane 18.5 19.4 20.3 39.5 40.7 42.0n-Octane 32.0 33.0 34.0 57.0 57.8 59.0n-Dodecane 92.8 94.0 95.2 106.4 107.6 108.8D6733 01 (2016)3the end of analysis, divided by the maximum area slice ofN-octane obtained with the system performance mixture.10.2.4.1 Mea
47、surement of the StabilityCarry out one tem-perature programming defined in 10.1 without injecting anysample. Subtract the area slices at the start of the analysis withthose corresponding to 120 min (average of three slices).10.2.4.2 Stability StandardizationStandardization is car-ried out using the
48、system performance mixture defined in 7.12with the column temperature conditions defined in 10.1. Thevalue obtained in 10.2.4.1 is divided by the maximum areaslice of N-octane and multiplied by 100. The value obtainedmust be less than 2 %. If this is not the case, check for possibleleaks, or recondi
49、tion the column according to the manufactur-ers recommendations.10.3 Evaluation of the Linearity of the Split InjectorEvaluation is carried out using the system performance mixturedefined in 7.12 with the column temperature conditions definedin 10.1. The % (m/m) of each compound is determined fromthe corrected area % using the response factors for eachcompound given in Table A1.1 or Table A1.2. The relativepercent error is determined from the known mixture concen-trations according to Eq 5:Relative% error5100
