ASTM D5303-92(2007)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation:D5303 −92(Reapproved 2007)
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 (´) indicates an editorial change since the last revision or reapproval.
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
concentrations from 0.5 to 4.0 mg/kg (parts per million by 3.2 Arelativelylargevolumeofsampleisinjectedintoagas
mass). See Note 1. chromatograph having a single packed column, operated iso-
thermally at 10 to 50°C, that separates COS from propylene.
NOTE1—Thelowerlimitofthistestmethodisbelievedtobebelow0.1
COS is detected with a flame photometric detector.
mg/kg, depending on sample size and sensitivity of the instrumentation
being used. However, the cooperative testing program was conducted in
3.3 Calibrationdata,basedonpeakareas,areobtainedusing
the 0.5 to 4.0 range due to limitations in preparing commercial test
a known gas standard blend of COS in the range expected for
mixtures.
the sample. The COS peak area in the sample is measured and
1.2 The values stated in SI units are to be regarded as
the concentration of COS calculated.
standard. No other units of measurement are included in this
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 hazards
product quality. COS acts as a poison to commercial polym-
statements are given in Section 8.
erization catalysts, resulting in deactivation and costly process
downtime.
2. Referenced Documents
4.2 Accurate gas chromatographic determination of trace
2.1 ASTM Standards:
COSinpropyleneinvolvesuniqueanalyticalproblemsbecause
D3609Practice for Calibration Techniques Using Perme-
ofthechemicalnatureofCOSandidiosyncraciesoftracelevel
ation Tubes
analyses. These problems result from the reactive and absorp-
D4468Test Method for Total Sulfur in Gaseous Fuels by
tive nature of COS, the low concentration levels being
Hydrogenolysis and Rateometric Colorimetry
measured, the type of detector needed, and the interferences
E840PracticeforUsingFlamePhotometricDetectorsinGas
from the propylene sample matrix. This test method addresses
Chromatography
these analytical problems and ways to properly handle them to
assure 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
1 is recommended that they use the same calibration technique.
This test method is under the jurisdiction of ASTM Committee D02 on
PetroleumProductsandLubricantsandisthedirectresponsibilityofSubcommittee
5. Interferences
D02.D0.03 on Propylene.
Current edition approved Nov. 1, 2007. Published January 2008. Originally
5.1 Hydrogen sulfide (H S) or sulfur dioxide (SO ) can be
ϵ1
2 2
approved in 1992. Last previous edition approved in 2002 as D5303–92(2002) .
presentinthepropyleneandmustbeseparatedfromCOS.(See
DOI: 10.1520/D5303-92R07.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Note 2.)
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—H S and SO are separated from COS with the Carbopack
2 2
the ASTM website. BHT 100 columns or with the Chromosil 300 column.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D5303−92 (2007)
6. Apparatus 7.1 Air, zero grade.
6.1 Gas Chromatograph—Any gas chromatograph (GC) 7.2 Carbonyl sulfide (COS), lecture bottle, 97.5% min.
equipped with a flame photometric detector/electrometer sys-
(Warning—Toxic! See Section 8, Hazards.)
tem (FPD), as described in 6.2, may be used. A GC/FPD
7.3 Gas Calibration Blends, 1 to 10 mg/kg COS in either
equipped with an output signal linearizer is also permitted.
nitrogen, argon, propylene or a propylene/argon mixture.They
6.2 Detector System, flame photometric detector, either can be obtained from any commercial supplier or prepared as
singleordualburnerdesign.Noiselevelmustbenomorethan
shown in Appendix X1 or Test Method D4468.
one recorder chart division (see 6.5).The signal for COS must
7.4 Gas Sampling Syringe, 0.1, 1.0, and 5.0 mL.
be at least twice the noise level at the 0.1 mg/kg level. A
7.5 Gas Sampling Valve and Sample Loops, fluorocarbon or
discussion of this detector is presented in Practice E840. The
316 stainless steel. See Footnote B of Table 1.
electrometer used with the detector must have a sensitivity of
−12
10 A full scale ona1mV recorder to achieve optimum
7.6 Glass Vials, 125 cm.
detectability at lowest levels.
7.7 Hydrogen, pure grade, 99.9%.
6.3 Column—Any column that will effect the complete
7.8 Isooctane (2,2,4-trimethylpentane), sulfur free, mini-
separation of COS from propylene and other compounds
mum purity 99 mol%. (Warning—Flammable! Health Haz-
normally present in propylene concentrates, and that is suffi-
ard.)
ciently inert to preclude the loss of COS, may be used.
Columns that meet these criteria, and that were used in the
7.9 Nitrogen or Helium, 99.999% min.
cooperative study for this test method, are listed in Table 1.
7.10 TFE-fluorocarbon septa and aluminum seals for vials.
6.4 Sample Inlet System—Any gas sampling valve or gas
tightsyringethatwillpermitintroductionofupto5.0mLtothe
8. Hazards
column, and that will not cause any loss of COS, is suitable.
8.1 Carbonyl sulfide is toxic and narcotic in high concen-
6.5 Recorder—Any strip chart recorder with a full scale
trations,andupondecompositioncanliberatehydrogensulfide.
range of 1 mV, a maximum full scale balance time of 2 s, and
Exposure to dangerous concentrations of COS is most likely
a minimum chart speed of 0.5 cm/s, may be used.
when handling the pure component for preparation of standard
blends for assaying the COS calibration gas standards.
6.6 Data Handling System—Any commercially available
GC integrator or GC computer system capable of accurately
9. Sampling
integratingthearea(uVs)oftheCOSpeakissatisfactory.Data
systems that will linearize the logarithmic output of the FPD
9.1 Supply samples to the laboratory in high pressure
are also satisfactory.
cylinders coated internally with TFE-fluorocarbon, or other-
wise specially treated to reduce or eliminate loss of COS due
6.7 Sample Cylinders, 300 mLcapacity or larger, fluorocar-
to reaction with the cylinder walls.
bon lined stainless steel, Type DOT 3E, 12409 kPa (1800 psi)
working pressure.
9.2 The sample cylinder and contents should be at room
temperature prior to sampling to the chromatograph. Test
7. Reagents and Materials
samples as soon as possible after receipt.
NOTE3—CooperativestudiesindicatethatthemeasuredvalueforCOS
A
will decrease with time.
TABLE 1 Suitable GC Columns and Temperatures
Column Packing and Oven
B
9.3 Place the sample cylinder in a vertical position and use
Size, m × mm Tubing Type
Number Temperature, °C
either of the following two techniques to obtain a vaporized
1 0.9 × 3.78 SS Porapak R, 80/100 Mesh; 47
sample from the container for introduction into the GC.
C
2 1.4×3.78 TFE Carbopack BHT 100, 40/60
D
Mesh; 25,40 9.3.1 Connect the sample cylinder to the sampling valve on
D
3 1.8 × 3.78 TFE Carbopack BHT 100; 25,30
the chromatograph, using a minimum length of 316 ss tubing,
4 1.8 × 3.78 TFE Porapak Q, AW, 50/80 Mesh
so that sample is withdrawn from the bottom of the cylinder.
2.4 × 3.78 TFE (Above in Series); 74
5 2.4 × 3.78 SS Carbopack BHT 100; 47
Adjust the flow rate from the sample cylinder so that complete
6 2.8 × 3.78 TFE Carbopack BHT 100, 40/60
vaporization of the liquid occurs at the cylinder valve. A flow
Mesh; 50
rate of 5 to 10 bubbles/s through a water bubbler placed at the
7 3.6 × 3.78 TFE Carbopack BHT 100, 40/60
Mesh; 50
sample vent is sufficient (see Note 4).Turn the sampling valve
E
8 4.3 × 3.78 TFE Chromosil 300; 50
to the “flush” position and flush for approximately 15 s. Shut
9 6.1 × 3.78 TFE Hayes Sep Q, 80/100 Mesh; 65
off the cylinder valve and allow the pressure to drop to
A
These columns have been tested cooperatively and found suitable for use with
atmospheric.
this test method.
B
316 SS Tubing for columns or connection of sample cylinder to sampling system
NOTE 4—If the flow rate is too fast, warming of the valve can be
can be TFE lined internally to improve on system stability. This tubing is
required to avoid freezing and to ensure complete vaporization of the
commercially available from chromatography vendors.
C
sample.
TFE—Homopolymer of tetrafluoroethylene.
D
Identical columns used by different labs at different temperatures.
E 9.3.2 Alternatively,obtainasamplewithagastightsyringe.
Propyne (methyl acetylene) can interfere with COS using this column.
Aconvenient way to do this is to use flexible plastic tubing to
D5303−92 (2007)
connectthebottomofthesamplecylindertothewaterbubbler F 5 C/A (1)
and then to pierce the tubing with the syringe needle after flow
where:
is established.
F = calibration factor,
C = concentration, mg/kg, of COS in this test method, and
10. Preparation of Apparatus
A = area (uVs) of the COS peak in this test method.
10.1 Install in the GC according to the manufacturer’s
Fwillbeusedin(Eq2)in13.1.1.However,ifalinearizeris
instructionsanyofthecolumnsthatmeetthecriteriain6.3.Set
not used, or if the data system does not have a provision to
the instrument conditions as follows:
handle logarithmic output, use the method in 11.5.1 or the
10.1.1 Oven Temperature, as determined by column used,
alternate in 11.5.2, below:
10.1.2 Detector,
...