ASTM D2712-91(2010)
(Test Method)Standard Test Method for Hydrocarbon Traces in Propylene Concentrates By Gas Chromatography
Standard Test Method for Hydrocarbon Traces in Propylene Concentrates By Gas Chromatography
SIGNIFICANCE AND USE
The trace hydrocarbon compounds listed in Table 1 may have an effect in the commercial use of propylene concentrates, and information on their concentration is frequently necessary.
SCOPE
1.1 This test method covers the determination of 5 to 500 ppm each of ethylene, total butylenes, acetylene, methyl acetylene, propadiene, and butadiene in propylene concentrates.
1.2 The values stated in SI units are to be regarded as standard. The values given in parentheses are for information 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 appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
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Designation:D2712 −91(Reapproved 2010)
Standard Test Method for
Hydrocarbon Traces in Propylene Concentrates by Gas
Chromatography
This standard is issued under the fixed designation D2712; 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 4. Significance and Use
1.1 This test method covers the determination of 5 to 500
4.1 The trace hydrocarbon compounds listed in Table 1 may
ppm each of ethylene, total butylenes, acetylene, methyl
haveaneffectinthecommercialuseofpropyleneconcentrates,
acetylene, propadiene, and butadiene in propylene concen-
and information on their concentration is frequently necessary.
trates.
5. Apparatus
1.2 The values stated in SI units are to be regarded as
standard. The values given in parentheses are for information
5.1 Columns—Any column may be used provided it will
only.
resolve the trace compound peaks present in concentrations of
1.3 This standard does not purport to address all of the 20 ppm or more so that the resolution ratio, A/B, will not be
safety concerns, if any, associated with its use. It is the
less than 0.4, where A is the depth of the valley on either side
responsibility of the user of this standard to establish appro- of peak B and B is the height above the baseline of the smaller
priate safety and health practices and determine the applica- of any two adjacent peaks (see Fig. 1). For compounds present
bility of regulatory limitations prior to use. in concentrations of less than 20 ppm the ratioA/B may be less
than 0.4. In the case where the small-component peak is
2. Referenced Documents
adjacent to a large one, it may be necessary to construct the
baseline of the small peak tangent to the curve as shown in Fig.
2.1 ASTM Standards:
2. Butylenes need not be resolved from each other. Columns
E260 Practice for Packed Column Gas Chromatography
found to be acceptable together with operating conditions used
F307 Practice for Sampling Pressurized Gas for Gas Analy-
are shown in Table 2. Table 3 shows typical retention times.
sis
5.1.1 Columns may be constructed of 3.2 -mm ( ⁄8-in.), 6.4
-mm ( ⁄4-in.), or capillary tubing and usually need to be a
3. Summary of Test Method
minimum of 6 m (20 ft) in length. They usually have 20 to 40
3.1 A relatively large volume of sample is charged to a gas
g of liquid substrate to 100 g of solid support. If packed
partition chromatography apparatus which has a column that
columnsareused,theliquidmaybeplacedonthesolidsupport
willseparatethetracehydrocarbonconstituentsfromthemajor
by any suitable method, provided the column has the desired
components. Any column or combination of columns may be
resolution and sensitivity.
used provided they have the necessary resolution and the
detectingsystemhassufficientsensitivity.Severalcolumnsthat
NOTE 1—Separation of all the desired compounds on a single column
have been found satisfactory are given in 5.1. has been found by cooperators to be very difficult. Most laboratories have
found it necessary to use two or more columns. Typical instructions for
3.2 Calculation is performed by calculating the concentra-
preparing such columns may be found in Practice E260.
tion of the trace compound from its area relative to the area of
5.2 GasChromatograph—Any gas chromatography appara-
a standard compound of known concentration.
tus may be used provided the system has sufficient sensitivity
to detect the trace compounds of interest. For calculation
techniques utilizing a recorder, the signal for 20 ppm concen-
This test method is under the jurisdiction of ASTM Committee D02 on
tration shall be at least 5 chart divisions above the noise level
Petroleum Products, Liquid Fuels, and Lubricantsand is the direct responsibility of
Subcommittee D02.D0.03 on Propylene.
ona0to100 scale chart. The noise level must be restricted to
Current edition approved May 1, 2010. Published May 2010. Originally
a maximum of 2 chart divisions.When electronic integration is
E1
approved in 1968. Last previous edition approved in 2003 as D2712 – 91 (2003) .
employed, the signal for 20-ppm concentration must be at least
DOI: 10.1520/D2712-91R10.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or twice the noise level.
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 NOTE 2—A flame ionization detector is preferred. When using with
the ASTM website. relatively volatile liquid phases, such as HMPA, an additional 0.31-m
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D2712−91 (2010)
TABLE 1 Molecular Weight and Specific Gravity
6.4 Carrier Gases—Helium or Nitrogen. (Warning—
Compound Molecular Weight Specific Gravity, 60/60 Compressed gas under pressure.)
Propylene 42.08 0.5220
6.5 Hydrogen. (Warning—Compressed gas under pressure
Propane 44.09 0.5077
and flammable.)
6.6 Liquid Phase for Column—See Table 2.(Warning—
Hexamethylphosphoramide is a potential carcinogen.)
6.7 Solid Support—C firebrick or diatomaceous earth,
usually 40 to 60 or 60 to 80 mesh.
6.8 Stainless Steel Sample Cylinder, 300 to 500-cm
capacity,capableofwithstandingaminimumof1723kPagage
(250 psig).
6.9 SiliconeRubberSeptum,withsuitablefittingsforattach-
ment to sample cylinder.
6.10 Gas Syringe, 10-cm .
6.11 Vacuum Pump, capable of evacuating sample cylinder
FIG. 1 Illustration of A/B Ratio
to less than 2 mm Hg absolute pressure.
6.12 AluminumorStainlessSteelTubing, 0.61 m (2 ft), 3.2
1 1
mm ( ⁄8 in.), or 1.6 mm ( ⁄16 in.), outside diameter with fittings
on one end to connect to butadiene cylinder and the other end
modified so as to have an opening with an inside diameter of
about 0.5 mm larger than the outside diameter of the gas
syringe needle.
7. Sampling
7.1 This section is to be followed on all samples including
unknown samples and the synthetic standards.
7.2 Samples should be supplied to the laboratory in high-
pressure sample cylinders, obtained using the procedures
FIG. 2 Illustration of A/BRatio for Small-Component Peak
described in Practice F307 or similar methods.
7.3 Place the cylinder in a horizontal position in a safe
(1-ft) section of column containing uncoated solid support will aid in
reducing noise. location such as a hood. Check to see that the container is at
least one-half full by slightly opening the valve. If liquid is
5.3 Sample Introduction—Means shall be provided for in-
emitted (a white cloud of vapors) the container is at least
troducing a measured quantity of sample into the apparatus.
one-half full. Do not analyze any samples or use any synthetic
Pressure sampling devices may be used to inject a small
standard if the liquid in the container is less than this amount.
amount of the liquid directly into the carrier gas. Introduction
may be by means of a gas valve to charge the vaporized liquid.
7.4 Place the cylinder in a vertical position and repressurize
to 1723 kPa gage (250 psig) with the chromatographic carrier
6. Reagents and Materials
gas through the valve at the top of the cylinder, ensuring that
6.1 Hydrocarbons, for peak identification, including
no air enters during the operation.
propylene, ethylene, ethane, acetylene, methyl acetylene,
7.5 Use either of the following two procedures for obtaining
propadiene, propane, 1,3-butadiene, isobutylene, 1-butene, cis
a sample from the container:
and trans 2-butene, iso- and normal butane, and cyclopropane.
7.5.1 Using a Liquid Valve—Connect the cylinder to the
(Warning—Liquefied petroleum gas under pressure and flam-
liquid valve on the chromatograph using a minimum length of
mable.) Mixtures of these hydrocarbons may be used for
connecting tubing, so that sample is withdrawn from the
calibration provided there is no uncertainty as to the identity of
bottom of the cylinder and a liquid sample is obtained. The
the desired compound.
liquid valve on the chromatograph must be designed in such a
6.2 Propane or Propylene, for synthetic base stock contain-
mannerthatfullsamplepressurecanbemaintainedthroughthe
ing less than 2 ppm by weight of acetylene or 1,3-butadiene.
valve without leaking and that means are provided for trapping
(Warning—Liquefied petroleum gas under pressure and flam-
a liquid sample in the chromatograph valve under static
mable.)
conditions of flow. With the exit of the chromatograph valve
6.3 Calibration Compounds—Acetylene and 1,3-butadiene closed open the valve on the cylinder. Slowly open the exit
99 % minimum purity. (Warning—Liquefied petroleum gas from the chromatograph valve so that liquid flows through the
under pressure and flammable.) connecting line and valve. Close the exits so that the liquid
D2712−91 (2010)
TABLE 2 Typical Column Conditions
Column 1 2 345678 9 10 11
Mixed
20 Mixed
A
Column: Series Series TCEP 80 MEEE Series
Liquid DMS Squa DMS ODPN UCON DMS None 80 % ODPN n C HMPA 8 DIDP None DMS Squa
SE-30
Weight,% 33 22 U 15 1515 25252030 20 3320
Solid Chrom Chrom Chrom Chrom Chrom Chrom SiGel Chrom Chrom Chrom Chrom Chrom SiGel Chrom Chrom
Mesh 60 to 80 60 to 80 100 80 to 100 U 60 to 80 U 30 to 60 30 to 60 60 to 80 60 to 80 60 to 80 40 to 60 60 to 80 60 to 80
Treatment none none U U U U U AW AW AW AW none FeCl none none
Length, ft 4 30 22 20 8 16 3.5 50 50 20 20 25 15 8 35
Inside diameter, 0.19 0.13 0.085 0.085 0.085 0.085 0.18 0.19 0.19 0.085 0.085 0.085 0.19 0.085 0.085
in.
Temperature:
Inlet, °C RT RT RT RT 160 70 RT RT RT RT RT
Detector, °C 150 RT 50 50 175 70 RT RT RT RT RT
Column, °C RT RT 50 50 30 70 RT RT RT RT RT
Sample:
Injection GV GV GV GV Syr Syr GV GV GV GV GV
Gas, cm 0.5 0.2 1 0.7 3.0 1 0.5 5 0.4 0.4 1
Split 40:1
Carrier:
Gas He He He He He He H He He He He
cm /min 50 22 24 42 40 40 17 60 30 30 52
Detector:
Type FI TC FI TC FI TC FI FI FI FI FI
Voltage 8 12 70
Recorder:
Range, mV 1 1 511155 1 1 1
in./h 30 60 30 30 30 30 30 30 60 60 30
Measurement Tri Plan Plan Plan PH PH PH PW/2 Tri Tri Tri
Abbreviations:
AW Acid washed ODPN β,β'-oxydipropionitrile
Chrom “Chromosorb” P (trademark of Johns-Manville Products Corp.) PH Peak height
DIDP Diisodecyl phthalate Plan Planimeter
DMS 2,4-dimethyl sulfolane PW/2 Peak height × width at ⁄3 height
FeCl Ferric chloride, modified RT Room temperature
FI Flame ionization SE-30 SE-30 gum rubber
GV Gas valve SiGel Silica gel
He
...
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