ASTM D7900 - 25 用气相色谱法测定稳定原油中轻质烃的标准试验方法

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Designation: D7900 −25
Standard Test Method for
Determination of Light Hydrocarbons in Stabilized Crude
Oils by Gas Chromatography
1
This standard is issued under the ﬁxed designation D7900; 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*
1.1 This test method speciﬁes a method to determine the
boiling range distribution of hydrocarbons in stabilized crude
oil up to and including n-nonane. A stabilized crude oil is
deﬁned as having a Reid Vapor Pressure equivalent to or less
than 82.7 kPa. The results of this test method can be combined
with those from Test Method D7169 and IP 545 to give a full
boiling point distribution of a crude oil (see Appendix X3).
1.2 The values stated in SI units are to be regarded as the
standard. The values given in parentheses are provided for
information purposes only.
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 appro-
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use.
1.4 This international standard was developed in accor-
dance with internationally recognized principles on standard-
ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
2
D323 Test Method for Vapor Pressure of Petroleum Products
(Reid Method)
D4057 Practice for Manual Sampling of Petroleum and
Petroleum Products
D4175 Terminology Relating to Petroleum Products, Liquid
Fuels, and Lubricants
D4177 Practice for Automatic Sampling of Petroleum and
Petroleum Products
D5134 Test Method for Detailed Analysis of Petroleum
Naphthas through n-Nonane by Capillary Gas Chroma-
tography
D6729 Test Method for Determination of Individual Com-
ponents in Spark Ignition Engine Fuels by 100 Metre
Capillary High Resolution Gas Chromatography
D6730 Test Method for Determination of Individual Com-
ponents in Spark Ignition Engine Fuels by 100-Metre
Capillary (with Precolumn) High-Resolution Gas Chro-
matography
D6733 Test Method for Determination of Individual Com-
ponents in Spark Ignition Engine Fuels by 50-Metre
Capillary High Resolution Gas Chromatography
D7169 Test Method for Boiling Point Distribution of
Samples with Residues Such as Crude Oils and Atmo-
spheric and Vacuum Residues by High Temperature Gas
Chromatography
E355 Practice for Gas Chromatography Terms and Relation-
ships
2.2 Energy Institute Standards:
3
IP 475 Manual Sampling
IP 476 Automatic Pipeline Sampling
IP 545 Crude Petroleum and Petroleum Products—
Determination of Boiling Range Distribution of Crude Oil
2.3 ISO Standard:
4
ISO 4259 Petroleum Products—Determination and Applica-
tion of Precision Data in Relation to Methods of Test
3. Terminology
3.1 Deﬁnitions—This test method makes reference to many
common petroleum and gas chromatographic procedures terms
and relationships. Detailed deﬁnitions can be found in Termi-
nology D4175 and Practice E355.
4. Summary of Test Method
4.1 An amount of internal standard is quantitatively added
to an aliquot of the stabilized crude oil. A portion of this
mixture is injected into a pre-column in series via a splitter
1
This test method is under the jurisdiction of ASTM Committee D02 on
Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of
Subcommittee D02.04.0L on Gas Chromatography Methods.
Current edition approved May 1, 2025. Published June 2025. Originally
approved in 2013. Last previous edition approved in 2023 as D7900 – 23. DOI:
10.1520/D7900-25.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at www.astm.org/contact. For Annual Book of
ASTM Standards volume information, refer to the standard’s Document Summary
page on the ASTM website.
3
Information on Energy Institute Standards can be obtained from the Energy
Institute at www.energyinst.org.
4
Available from American National Standards Institute (ANSI), 25 W. 43rd St.,
4th Floor, New York, NY 10036, http://www.ansi.org.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
1

with a capillary analytical column. When the n-nonane has

quantitatively passed to the analytical column, the pre-column

is back-ﬂushed to vent the higher boiling components. The

individual components are identiﬁed by comparison with

reference chromatograms and a database of hydrocarbon com-

pounds (see Appendix X1). The boiling point distribution up to

and including n-nonane (n-C9) is calculated.

5. Signiﬁcance and Use

5.1 Knowledge of the boiling point distribution of stabilized

crude oils is important for the marketing, scheduling, and

processing of crude oil in the petroleum industry. Test Method

D7169 and IP 545 purport to give such a distribution in crude

oils, but are susceptible to signiﬁcant errors in the light ends

portion of the distribution as well as in the mass recovery of the

whole crude oil due to the interference imposed by the diluent

solvent. This test method allows for more accurate determina-

tion of the front end of the boiling point distribution curve, in

addition to providing important C1 to C9 (nonane) component

level information, and more accurate mass recovery at C9

(nonane).

6. Apparatus

6.1 Gas Chromatograph, with the operational characteris-

tics given in Table 1.

6.2 Inlet—Atemperature programmable vaporizing (PVT)

or split/splitless inlet.

6.2.1 Carrier Gas Pneumatic Control—Constant carrier gas

pressure or ﬂow control is required.

6.3 Column—A fused silica-bonded polydimethylsiloxane

coated capillary column and pre-column are employed. See

Table 1 for suggested columns. The analytical column shall

elute hydrocarbons in a boiling point order. The eluate from the

injector passes through the pre-column before eluting onto the

analytical column.

6.4 Data System—A computer-based chromatography data

system capable of accurately and repeatedly measuring the

retention time and areas of eluting peaks. The system shall be

able to acquire data at a rate adequate to accurately measure 10

to 20 points around an individual peak. For the accelerated

methods (see Table 1), a sampling rate of at least 20 Hz is

recommended.

6.5 Sample Introduction—Sample introduction by means of

an automatic injection is highly recommended.

6.6 Flame Ionization Detector (FID), with sufficient sensi-

tivity to detect 0.01 % mass n-heptane with a signal to noise of

greater than ﬁve. When operating at this sensitivity level,

detector stability shall be such that a baseline drift of not more

than 1 % per hour is obtained. The detector shall be connected

to the column so as to avoid any cold spots. The detector shall

be capable of operating at a temperature equivalent to the

maximum column temperature used.

6.7 Pre-Column Conﬁgurations:

6.7.1 Heated Valve Switching Box Conﬁguration—For the

isothermal 1 m pre-column, a heated valve box is needed with

its own temperature control. The box will contain an automated

six-port valve, which is used to back-ﬂush the pre-column. The

six-port valve should be made out of material that will not be

corroded by the sample (some crude oils contain high amounts

of sulfur components). The valve shall be situated in a heated

isothermal oven and be attached to the injector, pre-column,

splitter, analytical column, and the detector without any cold

spots. An example conﬁguration is given in Fig. X2.1 in

Appendix X2. Alternatively, a Dean Switch type back-ﬂush of

the petroleum may also be employed in place of a rotary valve.

6.7.2 Injection Port Back-Flush Conﬁguration—A tempera-

ture programmable injection port capable of containing a

7.5 cm pre-column, and this injection port must be equipped

with a back-ﬂush option. This injector can be connected

TABLE 1 Typical Chromatographic Conditions

Pre-column Pre-column Analytical Accelerated

A B Analytical

Column Length—metres 1.0 m 0.075 m 50 or 100 m 40 m

Column Internal Diameter—mm 2 mm 2.5 mm 0.25 mm 0.10 mm

Phase Loading 5 %

10 % OV-101 on Chromosorb

80-100 mesh

Film Thickness 0.5 um

Injection Volume 0.1 µL 0.1 µL

Injector Split Ratio 100 : 1 600 : 1

Injector Temperature 300 °C 100 °C

Pre-column Temperature 200 °C 100 °C

Injector Prog. Rate °C/min 50 °C ⁄min

Final Injector Temperature 300 °C

Initial Oven Temperature 35 °C 35 °C

Hold Time 30 min 2.6 min

Oven Program Rate °C/min 2 °C ⁄min 50 °C ⁄min →45 °C

(hold time 3 min)

5 °C ⁄min →60 °C

(hold time 3 min)

9.5 °C ⁄min →

Final Oven Temperature 200 °C (hold time 20 min) 200 °C (hold time 1 min)

Flame Ionization Detector 300 °C 300 °C

Phase type not reported except as indicated, assumed non-polar.

D7900 − 25

directly to the capillary column (Fig. X2.2,Appendix X2) or
via a splitter (Fig. X2.3,Appendix X2).
6.8 Analytical Balance, capable of weighing with an accu-
racy of 0.1 mg.
7. Reagents and Materials
7.1 Gas Chromatograph Gases—All of the following gases
shall have a purity of 99.995 % (V ⁄V) or greater. (Warning—
Gases are compressed. Some are ﬂammable, and all gases are
under high pressure.)
NOTE 1—These speciﬁcations can be obtained by proper use of ﬁltering
devices and meeting the FID speciﬁcations in 6.6.
7.1.1 Carrier Gas—Helium or hydrogen is required. Any
oxygen present shall be removed, for example, by a suitable
chemical ﬁlter. If hydrogen is employed as a carrier gas, the
user is advised to follow all manufacturer’s safety guidelines
for its use. (Warning—Hydrogen is an extremely ﬂammable
gas under high pressure.)
7.1.2 Detector Combustion Gases, Air, Hydrogen, and
Make-up Gas (Helium or Nitrogen). (Warning—Hydrogen is
an extremely ﬂammable gas under high pressure.) (Warning—
Compressed air is a gas under high pressure and supports
combustion.)
7.2 Internal Standard—The internal standard shall have
baseline resolution from any adjacent eluting peaks. Hexene-1
or 3,3–dimethylbutene-1 (99 % pure) have been found to be
suitable.
7.3 Valve Timing Mixture/Splitter Linearity Mix—A quanti-
tative mixture of approximately 1 % mass of each normal
alkane from pentane to decane in hexadecane (99+ % purity).
Accurately record the mass (g) of each normal alkane as well
as the hexadecane solvent and calculate the actual mass percent
of each alkane in the mixture.
7.4 Viscosity Agent, Carbon disulﬁde, 99+ % pure,
(Warning—Extremely ﬂammable and toxic liquid.) is used as
a viscosity reduction agent in the preparation of samples.
8. Sampling
8.1 Samples to be analyzed by this test method must be
obtained using the procedures outlined in Practice D4057 or
Practice D4177 (IP 475 and IP 476, respectively).
8.2 The test specimen to be analyzed must be homogeneous
and free of dust or undissolved material.
9. Preparation of Apparatus
9.1 Chromatograph—Place in service according to manu-
facturer’s instructions. Typical operating conditions are given
in Table 1.
9.2 Column Preparation—Condition analytical columns in
accordance with manufacturer’s instructions.
9.3 System Performance Speciﬁcation:
9.3.1 Skewness—Determine the skew of the n-hexane peak
by measuring the width of the leading part of the peak at 5 %
peak height (A) and the width of the following part of the peak
at 5 % peak height (B). The ratio (B)/(A) shall be not less than
1 or more than 4 (see Fig. 1).
9.3.2 Column Resolution—Determine the resolution be-
tween the internal standard and the nearest n-paraffin peak.
R52×
~
t2 2t1
!
⁄ 1.699
~
w1 1w2
!
(1)
where:
R= the column resolution,
t1 = the retention time of the ﬁrst peak (peak 1),
t2 = the retention time of the second peak (peak 2),
w1 = the peak width at half height of peak 1, and
w2 = the peak width at half height of peak 2.
For example, if Hexene-1 is used as the internal standard, the
resolution is determined between Hexene-1 and n-hexane. The
resolution shall be at least 2.0.
9.3.3 Detector Response Factor Calculations—Calculate
the ﬂame ionization detector response factor relative to
methane, which is considered to have a response factor of unity
(1), for each hydrocarbon group type of a particular carbon
number using Eq 2.
RRf 5
@
~
C
aw
×C
n
!
1
~
H
aw
×H
n
!
#
×0.7487
~
C
aw
×C
n
!
(2)
where:
RRf = relative response factor for a hydrocarbon type
group of a particular carbon number,
C
aw
= atomic mass of carbon, 12.011,
C
n
= number of carbon atoms in the hydrocarbon type
group, of a particular carbon number,
H
aw
= atomic mass of hydrogen, 1.008,
H
n
= number of hydrogen atoms in the hydrocarbon type
group of a particular carbon number, and
0.7487 = factor to normalize the result to a methane re-
sponse of unity, (1).
9.3.4 Determination of Back-Flush Time—With the pre-
column and analytical column in series, inject an aliquot of the
pre-column switch test mixture (7.3) and determine the ratio of
the alkanes.
9.3.4.1 Non-Accelerated Analytical Column—Set the
switching time to one minute and repeat the analysis. Increase
or decrease the valve time to ensure the complete recovery of
the highest alkane required (for example, n-nonane) and partial
FIG. 1 Calculation of Peak Skewness (see 9.3.1)
D7900 − 25
3

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标签： #标准试验 #试验方法 #标准试验方法

摘要：

本页详细介绍 ASTM D7900 - 25 标准，即使用气相色谱法测定稳定原油中轻质烃含量的标准试验方法。该标准旨在为石油化工、炼油及质量控制实验室提供一种准确、可靠的分析流程，以定量测定稳定原油中从甲烷到正壬烷（通常包括 C1-C9）的轻质烃组分。通过优化色谱柱选择、升温程序及校准技术，该方法能够有效消除基质干扰，确保检测结果在精密度与准确性上符合国际规范。本内容适用于从事原油评价、加工工艺优化、产品合规检测以及贸易交接的工程师、技术专家与质量管理人员，帮助其快速掌握标准要点，实现实验操作与

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