ASTM D6229-06 (2025) 用毛细管气相色谱法测定烃类溶剂中痕量苯的标准试验方法

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Designation: D6229 −06 (Reapproved 2025)
Standard Test Method for
Trace Benzene in Hydrocarbon Solvents by Capillary Gas
Chromatography
1
This standard is issued under the ﬁxed designation D6229; 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 covers the determination by capillary
gas chromatography of trace benzene in hydrocarbon solvents
at levels from 1.0 vppm to 2400 vppm.
NOTE 1—Lower levels of benzene may be determined by this test
method. However the gas chromatography (GC) will have to be modiﬁed
from those speciﬁed in this test method. The precision of the method may
not apply to these lower benzene levels.
1.2 For hazard information and guidance, see the supplier’s
Safety Data Sheet.
1.3 The values stated in SI units are to be regarded as the
statement. The values in parenthesis are given for information
only and are not necessarily the exact equivalent of the SI unit
values.
1.4 For purposes of determining conformance of an ob-
served or a calculated value using this test method to relevant
speciﬁcations, test result(s) shall be rounded off “to the nearest
unit” in the last right-hand digit used in expressing the
speciﬁcation limit, in accordance with Practice E29.
1.5 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.
1.6 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
D4367 Test Method for Benzene in Hydrocarbon Solvents
by Gas Chromatography
E29 Practice for Using Signiﬁcant Digits in Test Data to
Determine Conformance with Speciﬁcations
E300 Practice for Sampling Industrial Chemicals
2.2 ASTM Adjuncts:
D2PP Determination of Precision and Bias Data
3
3. Summary of Test Method
3.1 A given volume of the sample is introduced into a gas
chromatograph equipped with two capillary columns con-
nected in series by switching valve. The specimen passes ﬁrst
through a short capillary column with a bounded nonpolar
phase where the components are separated by boiling point.
After octane has eluted from the ﬁrst column, the components
heavier than octane are back-ﬂushed to vent. The octane and
lighter components then pass through a second capillary
column with bounded polar phase where the aromatic and
nonaromatic components are separated. The eluted compo-
nents are detected by a ﬂame ionization detector, and the peak
areas are integrated electronically. The concentration of ben-
zene is calculated by a data processor using a response factor
determined by external standard technique.
4. Signiﬁcance and Use
4.1 This test method is similar to Test Method D4367 with
the exception that capillary columns are used and intended for
trace level of benzene in hydrocarbon solvents. The need for
1
This test method is under the jurisdiction of ASTM Committee D01 on Paint
and Related Coatings, Materials, and Applications and is the direct responsibility of
Subcommittee D01.35 on Solvents, Plasticizers, and Chemical Intermediates
Current edition approved Jan. 1, 2025. Published January 2025. Originally
approved in 1998. Last previous edition approved in 2018 as D6229 – 06 (2018).
DOI: 10.1520/D6229-06R25.
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
Available from ASTM International Headquarters. Order Adjunct No.
ADJD6300.
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

trace benzene analysis in hydrocarbon solvents arose because
of the increase of more stringent regulation of benzene level in
these materials.
5. Apparatus
5.1 Chromatograph—Any gas chromatographic instrument
that has a backﬂush system operated by a switching valve
automatically, ﬂame ionization detector, and can be operated at
the conditions given in Table 1.
5.2 Detector—The ﬂame ionization detector shall have suf-
ﬁcient sensitivity to detect 0.1 vppm of benzene at a peak
height of 3 times the noise level.
5.3 Columns—one 2 m (6.5 ft), 0.53 mm inside diameter
fused silica capillary with 5 µm thick bounded methyl silicone
column and one 30 m (98.5 ft), 0.53 mm inside diameter fused
silica capillary with 0.5 µm thick bounded polyethylene glycol
column.
5.4 Switching Valve—A 6-port switching valve 175 °C
(347 °F) maximum temperature, housed in a separate,
temperature-controlled oven, that can be activated automati-
cally by the gas chromatograph.
5.5 Sample Inlet System—The sample inlet system shall be
capable of split injection typically at a 1:10 split ratio.
NOTE 2—An auto injector was used in the generation of the repeatabil-
ity value of this test method, and is recommended. Manual injection with
a syringe is acceptable; however, the observed precision may not apply.
5.6 Data Acquisition System:
5.6.1 Recorder—A 0 mv to 1 mv range recorder or
equivalent, with a full-scale response time of 2 s shall be used.
5.6.2 Integrator—Means shall be provided for determining
the area of the benzene peak. This can be done by means of an
electronic integrator or a computer based chromatography data
system. The integrator/computer system shall have standard
chromatographic software for determining the retention times
and areas of eluting peaks.
5.7 Microsyringe—5 µL capacity.
5.8 Pipets—measuring 1 mL and 2 mL, graduated in
0.01 mL: 5 mL, 10 mL, and 20 mL capacity.
5.9 Pipets—delivery 0.5 mL, 1 mL, 2 mL, 5 mL, 10 mL,
25 mL capacity.
5.10 Flasks—volumetric, 25 mL, 50 mL, 100 mL, and
500 mL capacity.
6. Reagents
6.1 Purity of Reagents—All reagents shall be reagent grade
chemicals with a minimum purity of 99 + mol %.
6.1.1 Benzene.
6.1.2 n-Hexane, benzene-free.
6.1.3 n-Octane, benzene-free.
6.1.4 n-Nonane, benzene-free.
7. Sampling
7.1 Take samples of solvents to be analyzed by this test
method using the procedures described in Practice E300.
8. Preparation and Conditioning of Capillary Columns
8.1 Both columns prescribed by this procedure shall be
obtained ready to use from reputable chromatographic suppli-
ers.
8.2 Columns shall be conditioned following column sup-
plier recommended procedures before use.
9. Preparation of Gas Chromatograph
9.1 Connect columns A and B to the 6–port switching valve
by referring to Fig. 1.
9.1.1 Adjust the operating conditions to those listed in Table
1, but do not turn on the detector. Check the system for leaks.
9.2 Adjust the column ﬂow rate as follows:
9.2.1 Set the switching valve in the forward ﬂow mode (Fig.
2(a)) and adjust the ﬂow controller to give the required column
ﬂow rate.
9.2.2 Set the switching valve in the backﬂush mode (Fig. 2
(b)) and check that the column ﬂow is as required.
9.2.3 Turn on the detector. Change the switching from the
forward ﬂow to the backﬂush mode several times and observe
the baseline. There shall be no baseline shift resulting from the
pressure surge when the switching valves are changed. (A
persistent drift indicates leaks somewhere in the system).
9.3 Determine the backﬂush activation time. The backﬂush
activation time varies for each column system and shall be
determined experimentally as follows:
9.3.1 Prepare a solution of 0.1 v % n–octane and 0.1 v %
n–nonane in benzene-free n–hexane. With the system in the
forward ﬂow mode, introduce 1µL of the n–octane/n–nonane in
n–hexane mixture. Allow the chromatogram to run until the n
–nonane has eluted from the second column and the chromato-
graphic trace has returned to baseline. Measure the time in
minutes from the injection until the signal goes back to
baseline after the n–octane peak. At this point all of the
n–octane but essentially none of the n–nonane shall have
eluted. One half of the measured time approximates the time to
backﬂush (see 9.3.3).
NOTE 3—Some minor adjustment of the backﬂush activation time may
be necessary for some samples.
TABLE 1 Instrument Conditions Found Satisfactory for
Measuring Trace Concentrations of Benzene in Hydrocarbon
Solvents
GC Parameter Values
Detector Flame ionization detector (FID)
Columns:
Length, m (A) 2; (B) 30
Inside diameter, mm (A) 0.53; (B) 0.53
Liquid phase, bonded (A) methyl silicone; (B) polyethylene glycol
Liquid phase thickness (A) 5 µm; (B) 0.5 µm
Switching value temperature 150 °C (302 °F)
Temperature programme:
Initial temperature 40 °C (104 °F)
Initial time hold 8 min
Ramp rate 20 °C (68 °F) ⁄min
Final temperature 200 °C (392 °F)
Final time hold 5 min
Sample size 1 µL
Split ratio 1:10
Column ﬂow (He carrier gas) 5.0 mL/min
Backﬂush to vent activation time 3.0 min
D6229 − 06 (2025)
2

FIG. 1 Columns Connections to Switching Valve

FIG. 2 Flow Switching System

D6229 − 06 (2025)

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标签： #标准试验 #管 #试验方法

摘要：

该标准规范文档介绍了 ASTM D6229-06 (2025) 标准，即采用毛细管气相色谱法测定烃类溶剂中痕量苯的试验方法。该方法适用于分析多种烃类溶剂中的痕量苯含量，具有高灵敏度和精确度，能够满足化工、石油及环境监测等领域对苯残留的严格检测要求。文档详细说明了样品前处理、色谱条件设置、定量分析步骤及结果计算方式，旨在帮助用户准确评估溶剂中苯的浓度，确保产品质量与安全合规。该标准最新版本于2025年确认，延续了原有技术规范，适用于实验室质量控制、溶剂生产监控及进出口检验等相关场景。通过该方法，用

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ASTM D6229-06 (2025) 用毛细管气相色谱法测定烃类溶剂中痕量苯的标准试验方法

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