ASTM D5303-92(2002)e1

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An American National Standard
e1
Designation: D 5303 – 92 (Reapproved 2002)
Standard Test Method for
Trace Carbonyl Sulfide in Propylene by Gas
Chromatography
This standard is issued under the fixed designation D5303; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
e NOTE—Warning notes were editorially moved into the standard text in March 2003.
1. Scope COS, calibrating the detector, quantitating COS content in the
sample, and assaying the gas standard. General comments and
1.1 This test method covers the determination of traces of
recommended techniques are given.
carbonyl sulfide (COS) in propylene. It is applicable to COS
3.2 Arelativelylargevolumeofsampleisinjectedintoagas
concentrations from 0.5 to 4.0 mg/kg (parts per million by
chromatograph having a single packed column, operated iso-
mass). See Note 1.
thermally at 10 to 50°C, that separates COS from propylene.
NOTE 1—Thelowerlimitofthistestmethodisbelievedtobebelow0.1
COS is detected with a flame photometric detector.
mg/kg, depending on sample size and sensitivity of the instrumentation
3.3 Calibrationdata,basedonpeakareas,areobtainedusing
being used. However, the cooperative testing program was conducted in
a known gas standard blend of COS in the range expected for
the 0.5 to 4.0 range due to limitations in preparing commercial test
the sample. The COS peak area in the sample is measured and
mixtures.
the concentration of COS calculated.
1.2 The values stated in SI units are to be regarded as the
3.4 The COS gas standard blend is assayed prior to use for
standard.
calibration.
1.3 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
4. Significance and Use
responsibility of the user of this standard to establish appro-
4.1 Inprocessesproducingpropylene,COSusuallyremains
priate safety and health practices and determine the applica-
withtheC hydrocarbonsandmustberemoved,sinceitaffects
bility of regulatory limitations prior to use. Specific precau-
product quality. COS acts as a poison to commercial polymer-
tionary statements are given in Section 8.
ization catalysts, resulting in deactivation and costly process
downtime.
2. Referenced Documents
4.2 Accurate gas chromatographic determination of trace
2.1 ASTM Standards:
COSinpropyleneinvolvesuniqueanalyticalproblemsbecause
D3609 Practice for Calibration Techniques using Perme-
ofthechemicalnatureofCOSandidiosyncraciesoftracelevel
ation Tubes
analyses. These problems result from the reactive and absorp-
D4468 Test Method for Total Sulfur in Gaseous Fuels by
tive nature of COS, the low concentration levels being mea-
Hydrogenolysis and Rateometric Colorimetry
sured, the type of detector needed, and the interferences from
E840 Practice for Using Flame Photometric Detectors in
the propylene sample matrix. This test method addresses these
Gas Chromatography
analyticalproblemsandwaystoproperlyhandlethemtoassure
accurate and precise analyses.
3. Summary of Test Method
4.3 Thistestmethodprovidesabasisforagreementbetween
3.1 A procedure is given for removing a sample from the
two laboratories when the determination of trace COS in
sample cylinder, separating COS from propylene, detecting
propylene is important. The test method permits several
calibrationtechniques.Forbestagreementbetweentwolabs,it
This test method is under the jurisdiction of ASTM Committee D02 on
is recommended that they use the same calibration technique.
Petroleum Products and Lubricants and is the direct responsibility of Subcommittee
D02.D0.03 on Propylene.
5. Interferences
Current edition approved Dec. 10, 2002. Published April 2003. Originally
approved in 1992. Last previous edition approved in 1997 as D5303–92 (1997). 5.1 Hydrogen sulfide (H S) or sulfur dioxide (SO ) can be
2 2
Annual Book of ASTM Standards, Vol 11.03.
presentinthepropyleneandmustbeseparatedfromCOS.(See
Annual Book of ASTM Standards, Vol 05.06.
Note 2.)
Annual Book of ASTM Standards, Vol 03.06.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
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D 5303 – 92 (2002)
NOTE 2—H S and SO are separated from COS with the Carbopack
7.2 Carbonyl sulfide (COS), lecture bottle, 97.5% min.
2 2
BHT 100 columns or with the Chromosil 300 column.
(Warning—Toxic! See Section 8, Hazards.)
7.3 Gas Calibration Blends, 1 to 10 mg/kg COS in either
6. Apparatus
nitrogen, argon, propylene or a propylene/argon mixture.They
6.1 Gas Chromatograph—Any gas chromatograph (GC)
can be obtained from any commercial supplier or prepared as
equipped with a flame photometric detector/electrometer sys-
shown in Appendix X1 or Test Method D4468.
tem (FPD), as described in 6.2, may be used. A GC/FPD
7.4 Gas Sampling Syringe, 0.1, 1.0, and 5.0 mL.
equipped with an output signal linearizer is also permitted.
7.5 Gas Sampling Valve and Sample Loops, fluorocarbon or
6.2 Detector System, flame photometric detector, either
316 stainless steel. See Footnote B of Table 1.
singleordualburnerdesign.Noiselevelmustbenomorethan
7.6 Glass Vials, 125 cm.
one recorder chart division (see 6.5). The signal for COS must
7.7 Hydrogen, pure grade, 99.9%.
be at least twice the noise level at the 0.1 mg/kg level. A
discussion of this detector is presented in Practice E840. The 7.8 Isooctane (2,2,4-trimethylpentane), sulfur free, mini-
electrometer used with the detector must have a sensitivity of
mum purity 99 mol%. (Warning—Flammable! Health Haz-
−12
10 A full scale ona1mV recorder to achieve optimum
ard.)
detectability at lowest levels.
7.9 Nitrogen or helium, 99.999% min.
6.3 Column—Any column that will effect the complete
7.10 TFE-fluorocarbon septa and aluminum seals for vials.
separation of COS from propylene and other compounds
normally present in propylene concentrates, and that is suffi-
8. Hazards
ciently inert to preclude the loss of COS, may be used.
8.1 Carbonyl sulfide is toxic and narcotic in high concen-
Columns that meet these criteria, and that were used in the
trations,andupondecompositioncanliberatehydrogensulfide.
cooperative study for this test method, are listed in Table 1.
Exposure to dangerous concentrations of COS is most likely
6.4 Sample Inlet System—Any gas sampling valve or gas
when handling the pure component for preparation of standard
tightsyringethatwillpermitintroductionofupto5.0mLtothe
blends for assaying the COS calibration gas standards.
column, and that will not cause any loss of COS, is suitable.
6.5 Recorder—Any strip chart recorder with a full scale
9. Sampling
range of 1 mV, a maximum full scale balance time of 2 s, and
a minimum chart speed of 0.5 cm/s, may be used.
9.1 Supply samples to the laboratory in high pressure
6.6 Data Handling System—Any commercially available
cylinders coated internally with TFE-fluorocarbon, or other-
GC integrator or GC computer system capable of accurately
wise specially treated to reduce or eliminate loss of COS due
integratingthearea(uVs)oftheCOSpeakissatisfactory.Data
to reaction with the cylinder walls.
systems that will linearize the logarithmic output of the FPD
9.2 The sample cylinder and contents should be at room
are also satisfactory.
temperature prior to sampling to the chromatograph. Test
6.7 Sample Cylinders, 300 mLcapacity or larger, fluorocar-
samples as soon as possible after receipt.
bon lined stainless steel, Type DOT 3E, 12409 kPa (1800 psi)
NOTE 3—CooperativestudiesindicatethatthemeasuredvalueforCOS
working pressure.
will decrease with time.
7. Reagents and Materials
9.3 Place the sample cylinder in a vertical position and use
7.1 Air, zero grade.
either of the following two techniques to obtain a vaporized
sample from the container for introduction into the GC.
A
TABLE 1 Suitable GC Columns and Temperatures
9.3.1 Connect the sample cylinder to the sampling valve on
Column Packing and Oven
B
Size, m 3 mm Tubing Type the chromatograph, using a minimum length of 316 ss tubing,
Number Temperature, °C
so that sample is withdrawn from the bottom of the cylinder.
10.9 3 3.78 SS Porapak R, 80/100 Mesh; 47
Adjust the flow rate from the sample cylinder so that complete
C
21.4 3 3.78 TFE Carbopack BHT 100, 40/60
D
vaporization of the liquid occurs at the cylinder valve. A flow
Mesh; 25,40
D
31.8 3 3.78 TFE Carbopack BHT 100; 25,30
rate of 5 to 10 bubbles/s through a water bubbler placed at the
41.8 3 3.78 TFE Porapak Q, AW, 50/80 Mesh
sample vent is sufficient (see Note 4).Turn the sampling valve
2.4 3 3.78 TFE (Above in Series); 74
to the “flush” position and flush for approximately 15 s. Shut
52.4 3 3.78 SS Carbopack BHT 100; 47
62.8 3 3.78 TFE Carbopack BHT 100, 40/60
off the cylinder valve and allow the pressure to drop to
Mesh; 50
atmospheric.
73.6 3 3.78 TFE Carbopack BHT 100, 40/60
Mesh; 50
E NOTE 4—If the flow rate is too fast, warming of the valve can be
84.3 3 3.78 TFE Chromosil 300; 50
required to avoid freezing and to ensure complete vaporization of the
96.1 3 3.78 TFE Hayes Sep Q, 80/100 Mesh; 65
sample.
A
These columns have been tested cooperatively and found suitable for use with
this test method.
9.3.2 Alternatively,obtainasamplewithagastightsyringe.
B
316 SS Tubing for columns or connection of sample cylinder to sampling
system can be TFE lined internally to improve on system stability. This tubing is Aconvenient way to do this is to use flexible plastic tubing to
commercially available from chromatography vendors.
connect the bottom of the sample cylinder to the water bubbler
C
TFE—Homopolymer of tetrafluoroethylene.
D and then to pierce the tubing with the syringe needle after flow
Identical columns used by different labs at different temperatures.
E
Propyne (methyl acetylene) can interfere with COS using this column. is established.
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D 5303 – 92 (2002)
10. Preparation of Apparatus
A = area (uVs) of the COS peak in this test method.
Fwillbeusedin(Eq2)in13.1.1.However,ifalinearizeris
10.1 Install in the GC according to the manufacturer’s
instructionsanyofthecolumnsthatmeetthecriteriain6.3.Set not used, or if the data system does not have a provision to
handle logarithmic output, use the method in 11.5.1 or the
the instrument conditions as follows:
alternate in 11.5.2, below:
10.1.1 Oven Temperature, as determined by column used,
11.5.1 Calculate the nanogram (ng) amounts of sulfur, as
10.1.2 Detector, 100 to 200°C, and
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