1、Designation: D 2789 95 (Reapproved 2005)An American National StandardStandard Test Method forHydrocarbon Types in Low Olefinic Gasoline by MassSpectrometry1This standard is issued under the fixed designation D 2789; the number immediately following the designation indicates the year oforiginal adopt
2、ion 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.1. Scope1.1 This test method covers the determination by massspectrometry of the tot
3、al paraffins, monocycloparaffins, dicy-cloparaffins, alkylbenzenes, indans or tetralins or both, andnaphthalenes in gasoline having an olefin content of less than3 volume % and a 95 % distillation point of less than 210C(411F) as determined in accordance with Test Method D86.Olefins are determined b
4、y Test Method D 1319,orbyTestMethod D 875.1.2 It has not been determined whether this test method isapplicable to gasoline containing oxygenated compounds (forexample, alcohols and ethers).1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is
5、 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. Referenced Documents2.1 ASTM Standards:2D86 Test Method for Distillation of Petroleum Products atAtmospheric PressureD 875
6、Test Method for Calculation of Olefins and Aromat-ics in Petroleum Distillates from Bromine Number andAcid Absorption3D 1319 Test Method for Hydrocarbon Types in LiquidPetroleum Products by Fluorescent Indicator Adsorption2D 2001 Test Method for Depentanization of Gasoline andNaphthas2D 2002 Test Me
7、thods for Isolation of Representative Satu-rates Fraction from Low-Olefinic Petroleum Naphthas33. Terminology3.1 Definitions of Terms Specific to This Standard:43.1.1 The summations of characteristic mass fragments aredefined as follows:3.1.1.1(43 paraffins!5total peak height of m/e143 1 57 1 71 1 8
8、5 1 99.(1)3.1.1.2(41 monocycloparaffins!5total peak height of m/e141 1 55 1 691 83 1 97. (2)3.1.1.3(67 dicycloparaffins!5total peak height of m/e167 1 68 1 81 1 821 95 1 96. (3)3.1.1.4(77 alkylbenzenes!5total peak height of m/e177 1 78 1 79 1 911 92 1 105 1 106 1 119 1 120 1 133 1 134 1 147 1 148 1
9、1611 162. (4)3.1.1.5(103 indans and tetralins!5total peak height of m/e1103 1 1041 117 1 118 1 131 1 132 1 145 1 146 1 159 1 160. (5)3.1.1.6(128 naphthalenes!5total peak height of m/e1128 1 141 6 1421 155 1 156. (6)3.1.1.7T 5 total ion intensity 5 (41 1 (43 1 (67 1 (77 1 (103 1 (128.(7)3.2 carbon nu
10、mber, by definition, is the average number ofcarbon atoms in the sample.3.3 Amass number with a plus sign as superscript is definedas the peak height associated with the same mass number.4. Summary of Test Method4.1 Samples are analyzed by mass spectrometry, based onthe summation of characteristic m
11、ass fragments, to determinethe concentration of the hydrocarbon types. The average1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.04 on Hydrocarbon Analysis.Current edition approved May 1, 2005.
12、 Published May 2005. Originallyapproved in 1969. Last previous edition approved in 2000 as D 2789 95 (2000)e1.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the st
13、andards Document Summary page onthe ASTM website.3Withdrawn4Equations in 3.1.1 are identical to those in 11.1.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.number of carbon atoms of the sample is estimated fromspectral data. Calcul
14、ations are made from calibration datawhich are dependent upon the average number of carbon atomsof the sample. Results are expressed in liquid volume percent.5. Significance and Use5.1 A knowledge of the hydrocarbon composition of gaso-line process streams, blending stocks and finished motor fuelsis
15、 useful in following the effect of changes in plant operatingconditions, diagnosing process upsets, blending finished prod-ucts and in evaluating the relationship between compositionand performance properties.6. Apparatus6.1 Mass SpectrometerAny mass spectrometer that passesthe performance test desc
16、ribed in Section 8.NOTE 1Calibration and precision data for this method were obtainedon Consolidated Electrodynamics Corp. Type 21-101, 21-102, and 21-103mass spectrometers. These instruments operated with an ion sourcetemperature at or near 250C and at a constant magnetic field of about3100 to 3500
17、 gauss. Laboratories using either Consolidated Electrody-namics Corp. mass spectrometers that operate with different parameters orinstruments other than this design should check the applicability of thecalibration data in Table 1. If necessary, individual laboratories shoulddevelop their own calibra
18、tion data using the blends described in Table 2.6.2 Sample Inlet SystemAny sample inlet system thatallows the introduction of the text mixture (8.2) without loss,contamination, or change of composition.NOTE 2Laboratory testing has shown that, unless a special samplingtechnique or a heated inlet syst
19、em is used, relatively large errors will occurin the determination of small quantities of indans, tetralins, and naphtha-lenes.6.3 ManometerAmanometer suitable for direct reading inthe 0 to 100-mtorr (0 to 13-Pa) range is optional.NOTE 3The expression mtorr as used in this procedure replaces theolde
20、r (micron) unit of pressure.6.4 Microburet or Constant-Volume Pipet.7. Reference Standards7.1 Samples of the following hydrocarbons will be required:2-methylpentane, 2,4-dimethylpentane, n-octane, methylcyclo-pentane, methylcyclohexane, cis-1,2-dimethylcyclohexane,TABLE 1 Calibration Data(43/T (41/T
21、 (67/T (77/T (103/T (128/T ReferenceAParaffins:C60.6949 0.3025 0.0019 0.0006 . . (1)C70.7379 0.2583 0.0027 0.0010 . . (3)C80.7592 0.2362 0.0032 0.0014 . . (3)C90.7462 0.2350 0.0052 0.0021 . 0.0113 (12)C100.7772 0.2007 0.0056 0.0014 . 0.0151 (13)Monocycloparaffins:C60.1234 0.8218 0.0460 0.0086 . . (1
22、)C70.0731 0.8213 0.0952 0.0104 . . (3)C80.0737 0.8279 0.0866 0.0117 . . (3)C90.0884 0.8029 0.0942 0.0140 0.0003 0.0003 (12)C100.1471 0.6272 0.2176 0.0080 . . (13)Dicycloparaffins:C80.0057 0.1848 0.7843 0.0246 0.0004 . (4)C90.0171 0.2270 0.7070 0.0483 0.0005 . (5)C100.0114 0.2973 0.6582 0.0324 0.0006
23、 . (6)Alkylbenzenes:C60.0004 0.0004 . 0.9992 . . (2)C70.0146 0.0120 0.0007 0.9726 . . (3)C80.0033 0.0112 0.0007 0.9488 0.0359 . (3)C90.0061 0.0218 0.0020 0.9103 0.0598 . (12)C100.0095 0.0350 0.0025 0.8656 0.0839 0.0034 (13)Indans and tetralins:C90.0144 0.0101 0.0002 0.1600 0.8154 . (7)C100.0062 0.01
24、23 0.0044 0.2314 0.7236 0.0222 (8)C110.0231 0.0199 0.0017 0.1619 0.7456 0.0477 (9)Naphthalenes:C10C110.01210.07020.00370.01400.00080.00110.05810.01720.00650.00180.91880.8957(10)(11)AReferences to source of calibration data:(1) National cooperative by letter of Nov. 22, 1965.(2) Local task group coop
25、erative by meeting of March 1966.(3) National cooperative by letter of Aug. 6, 1962.(4) API No. 448, 100 %, bicyclo-(3.3.0)-octane.(5) Shell data, 100 %, for 1-methyl-cis-(3.3.0)-bicyclooctane.(6) API No. 412, 100 %, trans-decalin.(7) Unweighted API No. 413 and No. 1214 spectra of indan.(8) API No.
26、1103, 13 %; API No. 1104, 13 %; API No. 941, 37 %; API No. 539, 37 %.(9) Unweighted averages of API Nos. 1216, 1106, 1107, 1108, 1109.(10) Unweighted average of local task group (3 laboratories) data.(11) Unweighted average of API No. 990 and No. 991.(12) National cooperative by letter of Oct. 11, 1
27、967.(13) Proposed Method of Test for Hydrocarbon Types in Low Olefinic Gasoline by Mass Spectrometry; Appendix VII D2-1958.D 2789 95 (2005)2benzene, toluene, and p-xylene (WarningExtremely flam-mable liquids. Benzene is a poison, carcinogen, and is harmfulor fatal if swallowed.). Only reagent grade
28、chemicals conform-ing to the specifications of the Committee on AnalyticalReagents of the American Chemical Society,5National Insti-tute of Standards and Technology (NIST) standard hydrocar-bon samples, or other hydrocarbons of equal purity should beused.8. Performance Test8.1 Calibration for Test M
29、ixtureCalibrate the instrumentin accordance with the manufacturers instructions for thecompounds listed in 7.1, using the same manipulative tech-nique as described in 10.2. Express the calibration data in unitsof peak height per unit of liquid volume (V) at constantsensitivity. Determine (41/V, (43/
30、 V, and (77/V for each ofthe reference standards and calculate a weighted average valuefor each hydrocarbon group type in accordance with thecomposition of the test mixture as described in 8.2. Constructan inverse from the averaged coefficients.NOTE 4The volume, V, ordinarily is expressed as microli
31、tres.NOTE 5A desk calculator frequently is used for the calculation of 8.1and in such cases small inverse terms can be undesirable. If necessary, itis permissible to divide all averaged coefficients by some suitable constant5Reagent Chemicals, American Chemical Society Specifications, AmericanChemic
32、al Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see Analar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockvi
33、lle,MD.TABLE 2 Compositions of Calibration MixturesComponent (Volume Percent) Paraffins Cyclo-paraffinsCyclo-Alkyl-benzenesComponent (Volume Percent) ParaffinsCyclo-paraffinsAlkyl-benzenesC6Blends C9Blendsn-Hexane 46 . . n-Nonane 33 . .2-Methylpentane 28 . . 2-Methyloctane 20 . .3-Methylpentane 20 .
34、 . 3-Methyloctane 16 . .2-2-Dimethylbutane 1 . . 4-Methyloctane 8 . .2,3-Dimethylbutane 5 . . 3-Ethylheptane 3 . .Cyclohexane . 46 . 2,6-Dimethylheptane 12 . .Methylcyclopentane . 54 . 2,2-Dimethylheptane 2 . .Benzene . . 100 3,3-Diethylpentane 1 . .C7Blends2,2,5-Trimethylhexane2,2,5-Trimethylhexane
35、21.n-Heptane 45 . . 2,4-Dimethyl-3-ethylpentane 1 . .2-Methylhexane 23 . . 2,2,3,3-Tetramethylpentane 1 . .3-Methylhexane 16 . . n-Propylcyclohexane . 1 .2,2-Dimethylpentane 4 . . Isopropylcyclohexane . 2 .2,3-Dimethylpentane 6 . . 1-Methyl-c-2-ethylcyclohexane . 3 .2,4-Dimethylpentane 5 . . 1-Methy
36、l-t-2-ethylcyclohexane . 4 .3,3-Dimethylpentane 1 . . 1-Methyl-c-3-ethylcyclohexane . 8 .Methylcyclohexane . 57 . 1-Methyl-t-3-ethylcyclohexane . 8 .Ethylcyclopentane . 9 . 1-Methyl-c-4-ethylcyclohexane . 4 .1,1-Dimethylcyclopentane . 4 . 1-Methyl-t-4-ethylcyclohexane . 5 .1,t-2-Dimethylcyclopentane
37、 . 14 . 1,c-2,c-3-trimethylcyclohexane . 2 .1,t-3-Dimethylcyclopentane . 16 . 1,t-2,t-3-trimethylcyclohexane . 3 .Toluene . . 100 1,t-2,c-3-trimethylcyclohexane . 3 .C8Blends1,t-2,c-4-trimethylcyclohexane1,t-2,t-4-trimethylcyclohexane.1515.n-Octane 39 . . 1,c-3,c-5-trimethylcyclohexane . 5 .2-Methyl
38、heptane 19 . . 1,c-3,t-5-trimethylcyclohexane . 5 .3-Methylheptane 16 . . n-Butylcyclopentane . 1 .4-Methylheptane 8 . . 1,c-2-Diethylcyclopentane . 12 .3-Ethylhexane 3 . . 1,t-2,c-3,t-4-tetramethylcyclopentane . 4 .2,3-Dimethylhexane 4 . . n-Propylbenzene . . 32,4-Dimethylhexane 5 . . Isopropylbenz
39、ene . . 12,5-Dimethylhexane 6 . . 1-Methyl-2-ethylbenzene . . 8Ethylcyclohexane . 20 . 1-Methyl-3-ethylbenzene . . 191,t-2-Dimethylcyclohexane . 18 . 1-Methyl-4-ethylbenzene . . 111,c-3-Dimethylcyclohexane . 25 . 1,2,3-Trimethylbenzene . . 101,t-4-Dimethylcyclohexane . 11 . 1,2,4-Trimethylbenzene .
40、. 361-Methyl-c-2-ethylcyclopentane . 7 . 1,3,5-Trimethylbenzene . . 121,1,3-Trimethylcyclopentane . 5 .1,t-2,c-3-Trimethylcyclopentane . 9 .1,t-2,c-4-Trimethylcyclopentane . 5 .Ethylbenzene . . 10p-Xylene . . 23m-Xylene . . 46o-Xylene . . 21D 2789 95 (2005)3prior to inversion in order to obtain larg
41、er values in the inverse.8.2 Test MixturePrepare the synthetic mixture by weightfrom reference standards5to obtain a final composition ap-proximating the following but accurately known within 60.07 %:Reference StandardLiquidVolumePercent inMixtureApproximateWeightin Gramsto Give5 mL of Mixture2-Meth
42、ylpentane 7.2 0.2372,4-Dimethylpentane 9.4 0.318n-Octane 16.6 0.587Methylcyclopentane 7.1 0.267Methylcyclohexane 10.0 0.387cis-1,2-Dimethylcyclohexane 15.5 0.620Benzene 7.7 0.341Toluene 10.0 0.436p-Xylene 16.5 0.714100.0 3.907Record the mass spectrum of the test mixture from m/e+32to 120 using the m
43、anipulative technique as described in 10.2.Compute (41/V, (43/V, and (77/V from the spectrum of thetest mixture and calculate the composition using these valuesand the inverse of 8.1. The calculated composition shouldagree with known concentrations within the following limits:PercentTotal paraffins
44、60.8Total cycloparaffins 61.3Total aromatics 60.7If the test mixture cannot be analyzed successfully, consid-eration should be given to interference, stability, sensitivity,resolution, sample handling, or ability of the analyst.8.3 BackgroundAfter pumping out the test mixture speci-fied in 10.2, sca
45、n the mass spectrum from m/e+40 to 100.Background peaks at 43 and 91 should be less than 0.1 % of thecorresponding peaks in the mixture spectrum. If both tests ofperformance are met, it may be presumed that the instrument issatisfactory for sample analysis.9. Sample Preparation9.1 Depentanize the sa
46、mple in accordance with Test MethodD 2001.9.2 Determine the olefin content of the depentanized samplein accordance with Test Methods D 1319 or D 875.10. Procedure10.1 Generally, mass spectrometers are in continuous op-eration and should require no additional preparation beforeanalyzing samples. If t
47、he spectrometer has been turned on onlyrecently, check its operation according to the manufacturersinstructions to ensure stability before proceeding. Then makethe performance test (Section 8).10.2 Obtaining the Mass SpectrumUsing a microburet6ora constant-volume pipet, introduce sufficient sample t
48、hroughthe inlet system to give a pressure of 20 to 60 mtorr (2.7 to 8.0Pa). Record the amount of sample introduced and the finalpressure after expansion into the inlet system when a microbu-ret and manometer are used. Recharge the sample untilpressure readings that differ by 1 % or less are obtained
49、.Attaining this pressure check means that a given microburet isbeing used at constant volume. When the pressure check isobtained, admit the sample to the mass spectrometer and recordthe mass spectrum of the sample from m/e+32 to 186.11. Calculation11.1 PeaksRead peak heights from the record of the massspectrum of the sample corresponding to m/e+ratios of 41, 43,55, 57, 67, 68, 69, 71, 77, 78, 79, 81, 82, 83, 84, 85, 86, 91, 92,95, 96, 97, 98, 99, 100, 103, 104, 105, 106, 112, 113, 114, 117,118, 119, 120, 126, 127, 128, 131, 132, 133, 134, 140, 141,14
