ASTM D6159-97
(Test Method)Standard Test Method for Determination of Hydrocarbon Impurities in Ethylene by Gas Chromatography
Standard Test Method for Determination of Hydrocarbon Impurities in Ethylene by Gas Chromatography
SCOPE
1.1 This test method is used for the determination of methane, ethane, propane, propene, acetylene, iso-butane, propadiene, butane, trans-2-butene, butene-1, isobutene, cis-2-butene, methyl acetylene and 1,3-butadiene in high-purity ethylene. The purity of the ethylene can be calculated by subtracting the total percentage of all impurities from 100.00 %. Since this test method does not determine all possible impurities such as CO, CO2, H2O, alcohols, nitrogen oxides, and carbonyl sulfide, as well as hydrocarbons higher than decane, additional tests may be necessary to fully characterize the ethylene sample.
1.2 Data are reported in this test method as ppmV (parts per million by volume). This test method was evaluated in an interlaboratory cooperative study in the concentration range of 4 to 340 ppmV (2 to 204 mg/kg). The participants in the interlaboratory cooperative study reported the data in non-SI units. Wherever possible, SI units are included.
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.
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An American National Standard
Designation: D 6159 – 97
Standard Test Method for
Determination of Hydrocarbon Impurities in Ethylene by Gas
Chromatography
This standard is issued under the fixed designation D 6159; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope graph is provided with a 6–port sampling valve and two wide
bore capillary columns connected in series. These columns are
1.1 This test method is used for the determination of
a dimethyl silicone column and a (porous layer open tubular
methane, ethane, propane, propene, acetylene, iso-butane,
column (PLOT) Al O /KCl column. A flame ionization detec-
2 3
propadiene, butane, trans-2-butene, butene-1, isobutene, cis-2-
tor is used for detection. The integrated detector signal (peak
butene, methyl acetylene and 1,3-butadiene in high-purity
areas) are corrected for detector response. The hydrocarbon
ethylene. The purity of the ethylene can be calculated by
impurities are determined and the total impurities are used to
subtracting the total percentage of all impurities from 100.00
determine the ethylene content.
%. Since this test method does not determine all possible
impurities such as CO, CO ,H O, alcohols, nitrogen oxides,
2 2
4. Significance and Use
and carbonyl sulfide, as well as hydrocarbons higher than
4.1 High-purity ethylene is required as a feedstock for some
decane, additional tests may be necessary to fully characterize
manufacturing processes and the presence of trace amounts of
the ethylene sample.
certain hydrocarbon impurities can have deleterious effects.
1.2 Data are reported in this test method as ppmV (parts per
This test method is suitable for setting specifications, for use as
million by volume). This test method was evaluated in an
an internal quality control tool, and for use in development or
interlaboratory cooperative study in the concentration range of
research work.
4 to 340 ppmV (2 to 204 mg/kg). The participants in the
4.2 This test method does not detect such impurities as H O,
interlaboratory cooperative study reported the data in non-SI
CO, CO , and alcohols that may be present in the sample.
units. Wherever possible, SI units are included.
Hydrocarbons higher than n-decane cannot be analyzed by this
1.3 This standard dose not purport to address all of the
test method, if present in the sample. Test Method D 2504
safety concerns, if any, associated with its use. It is the
addresses the analysis of noncondensable gases and Test
responsibility of the user of this standard to establish appro-
Method D 2505 addresses the analysis of CO . Guide D 5234
priate safety and health practices and determine the applica-
describes all potential impurities present in ethylene. These
bility of regulatory limitations prior to use.
standards should be consulted when determining the total
2. Referenced Documents concentration of impurities in ethylene.
2.1 ASTM Standards:
5. Apparatus
D 2504 Test Method for Noncondensable Gases in C and
2 5.1 Gas Chromatograph (GC), a gas chromatographic in-
Lighter Hydrocarbon Products by Gas Chromatography
strument provided with a temperature programmable column
D 2505 Test Method for Ethylene, Other Hydrocarbons, and
oven and a flame ionization detector (FID). Regulate the carrier
Carbon Dioxide in High-Purity Ethylene by Gas Chroma-
2 gas by pressure control.
tography
3 5.2 Detector—Use a flame ionization detector (FID) having
D 5234 Guide for Analysis of Ethylene Product
a sensitivity of approximately 2.0 ppmV (1.2 mg/kg) or less for
3. Summary of Test Method the compounds listed in 1.1. An FID was exclusively used in
the interlaboratory cooperative study.
3.1 A gaseous ethylene sample is analyzed as received. The
5.3 Column Temperature Programmer—The chromato-
gaseous sample is injected into a capillary gas chromatograph.
graph shall be capable of linear programmed temperature
A split-injector may or may not be used. The gas chromato-
operation over a range sufficient for separation of the compo-
nents of interest. Section 8 lists the recommended operating
This test method is under the jurisdiction of ASTM Committee D02 on
conditions. The programming rate shall be sufficiently repro-
Petroleum Products and Lubricantsand is the direct responsibility of D02.D on
ducible to obtain retention repeatability of 0.05 min (3 s)
Hydrocarbons for Chemical and Special Uses.
Current edition approved July 10, 1997. Published September 1997.
Annual Book of ASTM Standards, Vol 05.01.
3 4
Annual Book of ASTM Standards, Vol 05.03. This column is supplied by major column manufacturers.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
D 6159
throughout the scope of this analysis.
5.4 Columns—Couple the two columns in series with either
a glass press tight connector or a mini-connector equipped with
graphite ferrules.
5.4.1 Column 1, 50 m, 0.53 mm inside diameter (ID) KCl
deactivated Al O PLOT column. Relative retention is depen-
2 3
dent on the deactivation method of the column. Other deacti-
vated Al O plot columns using sulfates as the deactivating
2 3
agent were also used in the interlaboratory comparison.
5.4.2 Column 2, 30 m, 0.53 mm ID, 5μm film thickness
methyl silicone. This column improves the separation of
methyl acetylene, iso-pentane, and n-pentane.
5.5 Sample Inlet System—Two injection modes were used
FIG. 2 Valve On – Injection
for the interlaboratory cooperative study.
5.5.1 A gas sampling valve placed in an unheated zone of
the gas chromatograph injecting the sample directly into the
column.
5.5.2 A gas sampling valve placed in an unheated zone of
the gas chromatograph in conjunction with a splitter injector
heated with a variable temperature control.
5.6 Gas Sampling Valve and Injection System—Use a 6-port
valve provided with ⁄16 in. fittings as the sample injection
system. A typical valve arrangement is shown in Fig. 1 and Fig.
2. Use a 10–60μL loop as shown in Fig. 1. Use good valve
maintenance techniques to avoid such problems as dead
volumes, cold spots, long connections, and non-uniform heated
zones. The preferred carrier gas arrangement for sample
introduction is pressure regulation. Use a 6-port valve in
conjunction with a splitter injector. A typical arrangement is FIG. 3 Valve Off – Sample Loading
shown in Fig. 3 and Fig. 4. Use split ratios of 50:1 to 100:1 at
temperatures of 150°C to 200°C. Loop sizes of 200–500μL
were used in the interlaboratory study. When using a splitter it
is important to check linearity of the splitter. Inject the standard
blend at 50:1, 75:1, and 100:1 split ratios. Check the response
factors as determined in 9.1, and the factors shall not vary more
than 3 %.
5.7 Data Acquisition System—Use any integrator or com-
puterized data acquisition system for peak area integration, as
well as for recording the chromatographic trace.
6. Reagent Materials
6.1 Standard Mixture—Use a gravimetrically blended gas
standard containing levels of 2 to 204 mg/kg (4 to 340 ppmV)
FIG. 4 Valve On – Injection
of each of the trace components listed in Table 1 to calibrate
the detector’s response. The standard gas mixture shall be
prepared gravimetrically from known raw materials, and cross
contaminants shall be taken into account. The mixtures should
be certified analytically such that the gravimetric and analyti-
cally derived values agree to an acceptable tolerance; that is 6
1or 6 2 %. The concentration of the minor components in the
calibration standard shall be within 20 to 50 % above the
concentration of the process stream or samples.
6.2 Compressed Helium, gas having purity of 99.999 %, or
better, with a total hydrocarbon level of < 1ppmV.
NOTE 1—Compressed helium is a gas under high pressure.
6.3 Compressed Hydrogen, gas used as fuel in the FID
FIG. 1 Valve Off – Sample Loading detector (less than 1.0 ppmV hydrocarbon impurities).
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
D 6159
TAB
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