ASTM D2789-95(2005)
(Test Method)Standard Test Method for Hydrocarbon Types in Low Olefinic Gasoline by Mass Spectrometry
Standard Test Method for Hydrocarbon Types in Low Olefinic Gasoline by Mass Spectrometry
SIGNIFICANCE AND USE
A knowledge of the hydrocarbon composition of gasoline process streams, blending stocks and finished motor fuels is useful in following the effect of changes in plant operating conditions, diagnosing process upsets, blending finished products and in evaluating the relationship between composition and performance properties.
SCOPE
1.1 This test method covers the determination by mass spectrometry of the total paraffins, monocycloparaffins, dicycloparaffins, alkylbenzenes, indans or tetralins or both, and naphthalenes in gasoline having an olefin content of less than 3 volume % and a 95 % distillation point of less than 210C (411F) as determined in accordance with Test Method D 86. Olefins are determined by Test Method D 1319, or by Test Method D 875.
1.2 It has not been determined whether this test method is applicable to gasoline containing oxygenated compounds (for example, alcohols and ethers).
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
General Information
Relations
Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: D2789 – 95 (Reapproved 2005)
Standard Test Method for
Hydrocarbon Types in Low Olefinic Gasoline by Mass
Spectrometry
This standard is issued under the fixed designation D2789; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 3. Terminology
1.1 This test method covers the determination by mass 3.1 Definitions of Terms Specific to This Standard:
spectrometry of the total paraffins, monocycloparaffins, dicy- 3.1.1 The summations of characteristic mass fragments are
cloparaffins, alkylbenzenes, indans or tetralins or both, and defined as follows:
naphthalenes in gasoline having an olefin content of less than 3.1.1.1
3 volume % and a 95 % distillation point of less than 210°C
(43 ~paraffins!5 total peak height of m/e 43 1 57 1 71 1 85 1 99.
(411°F) as determined in accordance with Test Method D86.
(1)
Olefins are determined by Test Method D1319,orbyTest
3.1.1.2
Method D875.
1.2 It has not been determined whether this test method is
(41 ~monocycloparaffins!5 total peak height of m/e 41 1 55 1 69
1 83 1 97. (2)
applicable to gasoline containing oxygenated compounds (for
example, alcohols and ethers).
3.1.1.3
1.3 This standard does not purport to address all of the
(67 ~dicycloparaffins!5 total peak height of m/e 67 1 68 1 81 1 82
safety concerns, if any, associated with its use. It is the
1 95 1 96. (3)
responsibility of the user of this standard to establish appro-
3.1.1.4
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
(77 ~alkylbenzenes!5 total peak height of m/e 77 1 78 1 79 1 91
1 92 1 105 1 106 1 119 1 120 1 133 1 134 1 147 1 148 1 161
2. Referenced Documents
1 162. (4)
2.1 ASTM Standards:
3.1.1.5
D86 Test Method for Distillation of Petroleum Products at
(103 ~indans and tetralins!5 total peak height of m/e 103 1 104
Atmospheric Pressure
1 117 1 118 1 131 1 132 1 145 1 146 1 159 1 160. (5)
D875 Method for Calculating of Olefins and Aromatics in
Petroleum Distillates from Bromine Number and Acid 3.1.1.6
Absorption 1
(128 ~naphthalenes!5 total peak height of m/e 128 1 141 6 142
D1319 Test Method for Hydrocarbon Types in Liquid
1 155 1 156. (6)
Petroleum Products by Fluorescent Indicator Adsorption
3.1.1.7
D2001 Test Method for Depentanization of Gasoline and
T 5 total ion intensity 5 (41 1 (43 1 (67 1 (77 1 (103 1 (128.
Naphthas
(7)
D2002 Test Methods for Isolation of Representative Satu-
3.2 carbon number, by definition, is the average number of
rates Fraction from Low-Olefinic Petroleum Naphthas
carbon atoms in the sample.
3.3 Amassnumberwithaplussignassuperscriptisdefined
This test method is under the jurisdiction of ASTM Committee D02 on
as the peak height associated with the same mass number.
PetroleumProductsandLubricants andisthedirectresponsibilityofSubcommittee
D02.04 on Hydrocarbon Analysis.
4. Summary of Test Method
Current edition approved May 1, 2005. Published May 2005. Originally
´1
approved in 1969. Last previous edition approved in 2000 as D2789 – 95 (2000) .
4.1 Samples are analyzed by mass spectrometry, based on
DOI: 10.1520/D2789-95R05.
the summation of characteristic mass fragments, to determine
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
the concentration of the hydrocarbon types. The average
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
3 4
Withdrawn. Equations in 3.1.1 are identical to those in 11.1.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D2789 – 95 (2005)
TABLE 1 Calibration Data
A
(43/T (41/T (67/T (77/T (103/T (128/T Reference
Paraffins:
C 0.6949 0.3025 0.0019 0.0006 . . (1)
C 0.7379 0.2583 0.0027 0.0010 . . (3)
C 0.7592 0.2362 0.0032 0.0014 . . (3)
C 0.7462 0.2350 0.0052 0.0021 . 0.0113 (12)
C 0.7772 0.2007 0.0056 0.0014 . 0.0151 (13)
Monocycloparaffins:
C 0.1234 0.8218 0.0460 0.0086 . . (1)
C 0.0731 0.8213 0.0952 0.0104 . . (3)
C 0.0737 0.8279 0.0866 0.0117 . . (3)
C 0.0884 0.8029 0.0942 0.0140 0.0003 0.0003 (12)
C 0.1471 0.6272 0.2176 0.0080 . . (13)
Dicycloparaffins:
C 0.0057 0.1848 0.7843 0.0246 0.0004 . (4)
C 0.0171 0.2270 0.7070 0.0483 0.0005 . (5)
C 0.0114 0.2973 0.6582 0.0324 0.0006 . (6)
Alkylbenzenes:
C 0.0004 0.0004 . 0.9992 . . (2)
C 0.0146 0.0120 0.0007 0.9726 . . (3)
C 0.0033 0.0112 0.0007 0.9488 0.0359 . (3)
C 0.0061 0.0218 0.0020 0.9103 0.0598 . (12)
C 0.0095 0.0350 0.0025 0.8656 0.0839 0.0034 (13)
Indans and tetralins:
C 0.0144 0.0101 0.0002 0.1600 0.8154 . (7)
C 0.0062 0.0123 0.0044 0.2314 0.7236 0.0222 (8)
C 0.0231 0.0199 0.0017 0.1619 0.7456 0.0477 (9)
Naphthalenes:
C 0.0121 0.0037 0.0008 0.0581 0.0065 0.9188 (10)
C 0.0702 0.0140 0.0011 0.0172 0.0018 0.8957 (11)
A
References to source of calibration data:
(1) National cooperative by letter of Nov. 22, 1965.
(2) Local task group cooperative 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. 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, 1967.
(13) Proposed Method of Test for Hydrocarbon Types in Low Olefinic Gasoline by Mass Spectrometry; Appendix VII D2-1958.
instruments other than this design should check the applicability of the
number of carbon atoms of the sample is estimated from
calibration data in Table 1. If necessary, individual laboratories should
spectral data. Calculations are made from calibration data
develop their own calibration data using the blends described in Table 2.
whicharedependentupontheaveragenumberofcarbonatoms
of the sample. Results are expressed in liquid volume percent.
6.2 Sample Inlet System—Any sample inlet system that
allows the introduction of the text mixture (8.2) without loss,
5. Significance and Use
contamination, or change of composition.
5.1 A knowledge of the hydrocarbon composition of gaso-
NOTE 2—Laboratory testing has shown that, unless a special sampling
line process streams, blending stocks and finished motor fuels
techniqueoraheatedinletsystemisused,relativelylargeerrorswilloccur
is useful in following the effect of changes in plant operating
in the determination of small quantities of indans, tetralins, and naphtha-
conditions, diagnosing process upsets, blending finished prod-
lenes.
ucts and in evaluating the relationship between composition
6.3 Manometer—Amanometersuitablefordirectreadingin
and performance properties.
the 0 to 100-mtorr (0 to 13-Pa) range is optional.
6. Apparatus
NOTE 3—The expression mtorr as used in this procedure replaces the
6.1 Mass Spectrometer—Anymassspectrometerthatpasses older µ (micron) unit of pressure.
the performance test described in Section 8.
6.4 Microburet or Constant-Volume Pipet.
NOTE 1—Calibration and precision data for this method were obtained
on Consolidated Electrodynamics Corp.Type 21-101, 21-102, and 21-103
7. Reference Standards
mass spectrometers. These instruments operated with an ion source
7.1 Samplesofthefollowinghydrocarbonswillberequired:
temperature at or near 250°C and at a constant magnetic field of about
2-methylpentane, 2,4-dimethylpentane, n-octane, methylcyclo-
3100 to 3500 gauss. Laboratories using either Consolidated Electrody-
namics Corp. mass spectrometers that operate with different parameters or pentane, methylcyclohexane, cis-1,2-dimethylcyclohexane,
D2789 – 95 (2005)
TABLE 2 Compositions of Calibration Mixtures
Cyclo-Alkyl- Cyclo- Alkyl-
Component (Volume Percent) Paraffins Cyclo-paraffins Component (Volume Percent) Paraffins
benzenes paraffins benzenes
C Blends C Blends
6 9
n-Hexane 46 . . n-Nonane 33 . .
2-Methylpentane 28 . . 2-Methyloctane 20 . .
3-Methylpentane 20 . . 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 . .
2,2,5-Trimethylhexane 2 . .
C Blends
2,2,5-Trimethylhexane 1 . .
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-Methyl-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 . 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 .
1,t-2,c-4-trimethylcyclohexane . 15 .
C Blends
1,t-2,t-4-trimethylcyclohexane . 15 .
n-Octane 39 . . 1,c-3,c-5-trimethylcyclohexane . 5 .
2-Methylheptane 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 . . 3
2,4-Dimethylhexane 5 . . Isopropylbenzene . . 1
2,5-Dimethylhexane 6 . . 1-Methyl-2-ethylbenzene . . 8
Ethylcyclohexane . 20 . 1-Methyl-3-ethylbenzene . . 19
1,t-2-Dimethylcyclohexane . 18 . 1-Methyl-4-ethylbenzene . . 11
1,c-3-Dimethylcyclohexane . 25 . 1,2,3-Trimethylbenzene . . 10
1,t-4-Dimethylcyclohexane . 11 . 1,2,4-Trimethylbenzene . . 36
1-Methyl-c-2-ethylcyclopentane . 7 . 1,3,5-Trimethylbenzene . . 12
1,1,3-Trimethylcyclopentane . 5 .
1,t-2,c-3-Trimethylcyclopentane . 9 .
1,t-2,c-4-Trimethylcyclopentane . 5 .
Ethylbenzene . . 10
p-Xylene . . 23
m-Xylene . . 46
o-Xylene . . 21
benzene, toluene, and p-xylene (Warning—Extremely flam- 8. Performance Test
mable liquids. Benzene is a poison, carcinogen, and is harmful
8.1 Calibration for Test Mixture—Calibrate the instrument
or fatal if swallowed.). Only reagent grade chemicals conform-
in accordance with the manufacturer’s instructions for the
ing to the specifications of the Committee on Analytical
compounds listed in 7.1, using the same manipulative tech-
Reagents of the American Chemical Society, National Insti-
nique as described in 10.2. Express the calibration data in units
tute of Standards and Technology (NIST) standard hydrocar-
of peak height per unit of liquid volume (V) at constant
bon samples, or other hydrocarbons of equal purity should be
sensitivity. Determine (41/V, (43/ V, and (77/V for each of
used.
the reference standards and calculate a weighted average value
for each hydrocarbon group type in accordance with the
Reagent Chemicals, American Chemical Society Specifications, American
composition of the test mixture as described in 8.2. Construct
Chemical Society, Washington, DC. For suggestions on the testing of reagents not
an inverse from the averaged coefficients.
listed by the American Chemical Society, see Analar Standards for Laboratory
Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, NOTE 4—The volume, V, ordinarily is expressed as microlitres.
MD.
D2789 – 95 (2005)
NOTE 5—Adesk calculator frequently is used for the calculation of 8.1
the inlet system to give a pressure of 20 to 60 mtorr (2.7 to 8.0
and in such cases small inverse terms can be undesirable. If necessary, it
Pa). Record the amount of sample introduced and the final
ispermissibletodivideallaveragedcoefficientsbysomesuitableconstant
pressure after expansion into the inlet system when a microbu-
prior to inversion in order to obtain larger values in the inverse.
ret and manometer are used. Recharge the sample until
8.2 Test Mixture—Prepare the synthetic mixture by weight
pressure readings that differ by 1 % or less are obtained.
from reference standards to obtain a final composition ap-
Attaining this pressure check means that a given microburet is
proximating the following but accurately known within 6
being used at constant volume. When the pressure check is
0.07 %:
obtained,admitthesampletothemassspectrometerandrecord
+
Approximate
the mass spectrum of the sample from m/e 32 to 186.
Liquid
Weight
Volume
Reference Standard in Grams
Percent in
to Give 11. Calculation
Mixture
5 mL of Mixture
11.1 Peaks—Read peak heights from the record of the mass
2-Methylpentane 7.2 0.237
+
2,4-Dimethylpentane 9.4 0.318 spectrum of the sample corresponding to m/e ratios of 41, 43,
n-Octane 16.6 0.587
55, 57, 67, 68, 69, 71, 77, 78, 79, 81, 82, 83, 84, 85, 86, 91, 92,
Methylcyclopentane 7.1 0.267
95, 96, 97, 98, 99, 100, 103, 104, 105, 106, 112, 113, 114, 117,
Methylcyclohexane 10.0 0.387
cis-1,2-Dimethylcyclohexane 15.5 0.620 118, 119, 120, 126, 127, 128, 131, 132, 133, 134, 140, 141,
Benzene 7.7 0.341
142, 145, 146, 147, 148, 154, 155, 156, 159, 160, 161, 162,
Toluene 10.0 0.436
168, 169, 170.
p-Xylene 16.5 0.714
11.1.1 Calculate the following combined peak heights by
100.0 3.907
adding together the indicated peaks:
+
Record the mass spectrum of the test mixture from m/e 32
11.1.1.1
to 120 using the manipulative technique as described in 10.2.
(43 5 m/e 43 1 57 1 71 1 85 1 99. (8)
Compute (41/V, (43/V, and (77/V from the spectrum of the
test mixture and calculate the composition using these values 11.1.1.2
and the inverse of 8.1. The calculated composition should
(41 5 m/e 41 1 55 1 69 1 83 1 97. (9)
...
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