ASTM D2426-93(2009)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: D2426 − 93(Reapproved 2009)
Standard Test Method for
Butadiene Dimer and Styrene in Butadiene Concentrates by
Gas Chromatography
This standard is issued under the fixed designation D2426; 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 components of interest present in the sample is determined
from the chromatogram by comparing their peak areas or
1.1 This test method covers the determination of butadiene
heights with those obtained from a synthetic sample.
dimer (4-vinylcyclohexene-1) and styrene in butadiene
concentrates, both recycle and specification grade.
4. Significance and Use
1.2 The values stated in SI units are to be regarded as
4.1 Butadiene dimer and styrene may be present as impuri-
standard. No other units of measurement are included in this
ties in commercial butadiene. This test method is suitable for
standard.
use in internal quality control and in establishing product
1.3 This standard does not purport to address all of the
specifications.
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
5. Apparatus
priate safety and health practices and determine the applica-
5.1 Chromatograph—Any chromatograph having either a
bility of regulatory limitations prior to use. For specific
thermal conductivity or flame ionization detector may be used.
precautionary statements see Sections 6 and 8.
The detector system shall have sufficient sensitivity to obtain a
deflection of at least 2 mm at a signal-to-noise ratio of at least
2. Referenced Documents
5:1for0.01weight%ofbutadienedimerandstyreneunderthe
2.1 ASTM Standards:
operating conditions prescribed in this test method.
D1657 Test Method for Density or Relative Density of Light
5.2 Recorder—A 0 to 1-mV, 0 to 5-mV, or 0 to 10-mV
Hydrocarbons by Pressure Hydrometer
recorder with a full-scale response time of2sor less, and with
D1945 Test Method for Analysis of Natural Gas by Gas
sufficient sensitivity to meet the requirements of 5.1.
Chromatography
D2593 Test Method for Butadiene Purity and Hydrocarbon 5.3 Column—Any column may be used that is capable of
Impurities by Gas Chromatography
resolving the butadiene dimer and styrene as discrete peaks,
quantitatively proportional to concentration and within an
2.2 Other Documents:
STP 109A Physical Constants of Hydrocarbons C to C elapsed time sufficiently short to be practical.
1 10
5.4 LiquidSamplingValve—Any liquid sampling valve may
3. Summary of Test Method
be used that will permit the reproducible introduction of the
3.1 The sample is introduced into a gas-liquid partition
butadiene concentrate as a liquid under its vapor pressure or
column. The components of interest are separated as they are
higher and in a quantity sufficient to meet the sensitivity and
transported through the column by a carrier gas, and their
resolution requirements in 5.1 and 5.3, respectively.
presenceintheeffluent is detected and recorded as a chromato-
gram. Packed columns are used, and either thermal conductiv-
6. Reagents and Materials
ity or ionization detectors are permissible. The quantity of the
6.1 4-vinylcyclohexene-1andStyrene, for calibration, purity
of not less than 99 %.
This test method is under the jurisdiction of ASTM Committee D02 on
6.2 Carrier Gas—Helium or hydrogen for use on thermal
Petroleum Products and Lubricants and is the direct responsibility of Subcommittee
conductivity detector units; or nitrogen, helium, or argon for
D02.D0.04 on C4 Hydrocarbons.
use on ionization detector units. (Warning—Compressed gas.
Current edition approved July 1, 2009. Published November 2009. Originally
ϵ1
approved in 1965. Last previous edition approved in 2004 as D2426–93(2004) .
Hazardous pressure.) (Warning—Hydrogen gas is flammable.
DOI: 10.1520/D2426-93R09.
Hazardous pressure.)
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
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. Suitable valves are commercially available.
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D2426 − 93 (2009)
TABLE 1 Columns and Conditions Used Successfully
Carbowax
Dow Silicone Carbowax Carbowax Polyethylene Barecowax
Silicone SE-30 20M + Dow
200 1500 1540 Glycol-6000 1035
Corning Hi Vac
Column length, m 1.5 4.6 3.7 15.2 3.1 3.7 6.1
Column diameter, mm 3.2 4.8 6.4 0.5 6.4 4.8 6.4
Column temperature, °C 85 110 100 75 100–128 155 140
Liquid phase, wt % 10 15 16 . 0.75 each 30 20
Support material Chromosorb P TFE-fluorocarbon Chromosorb P (Coated) Silica Chromosorb P Chromosorb P
Mesh 80–100 40–60 100–120 . . 30–50 60–80
Carrier flow, mL/min 19 60 60 15 30 171 60
A B
Detector HFI T.C. HFI HFI T.C. T.C. T.C.
Sample size, µL 0.77 20 0.07 1.54 1.03 8.69 3.0
Peak measurement triangulation triangulation integrator triangulation triangulation peak height planimeter
A
HFI = hydrogen flame ionization.
B
T.C. = thermal conductivity.
6.3 Liquid Phase, for column. a sensitivity setting that allows the maximum peak height.
Pressure the sample cylinder with a suitable gas to a pressure
NOTE 1—The following materials have been used successfully as liquid
sufficient to ensure no flashing in the line to the sampling valve
phases (see Table 1) :
or in the valve itself. Using the same sample size and
Carbowax 400, 1500, 1540
General Electric SE-30 silicone gum rubber
instrument conditions, i
...