ASTM D5507-99
(Test Method)Standard Test Method for Determination of Trace Organic Impurities in Monomer Grade Vinyl Chloride by Capillary Column/Multidimensional Gas Chromatography
Standard Test Method for Determination of Trace Organic Impurities in Monomer Grade Vinyl Chloride by Capillary Column/Multidimensional Gas Chromatography
SIGNIFICANCE AND USE
The multidimensional approach permits all of the trace impurities to be well separated from the main vinyl chloride peak, thereby improving quantitative accuracy over established packed column methods.
The minimum detection limit (MDL) for all components of interest has been shown to be well below 500 ppb for this test method.
SCOPE
1.1 This is a general-purpose capillary-based test method for the determination of trace level impurities in high-purity vinyl chloride. This test method uses serially coupled capillary PLOT columns in conjunction with the multidimensional techniques of column switching and cryogenic trapping to permit the complete separation of the 11 key vinyl chloride impurities in a single 25-min run. Note 1-There are no similar or equivalent ISO standards covering the primary subject of this test method.
1.2 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. Specific hazards statements are given in Section 8.
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation:D5507–99
Standard Test Method for
Determination of Trace Organic Impurities in Monomer
Grade Vinyl Chloride by Capillary Column/Multidimensional
Gas Chromatography
This standard is issued under the fixed designation D 5507; 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 of the liquid or gas sample is injected to enable the required
detection limits to be achieved.Apreliminary GC separation is
1.1 This is a general-purpose capillary-based test method
achieved on a 6-m pre-column, the purpose of which is to
for the determination of trace level impurities in high-purity
removethebulkofthevinylchloridepeakfromthetracepeaks
vinyl chloride. This test method uses serially coupled capillary
of interest. Two heart-cut transfers are made from this pre-
PLOT columns in conjunction with the multidimensional
column separation, which sends selected portions to a second
techniques of column switching and cryogenic trapping to
column for additional separation. These two cuts incorporate
permit the complete separation of the 11 key vinyl chloride
10 of the 11 trace impurities of interest, but they exclude 1,2
impurities in a single 25-min run.
ethylenedichlorideandthebulkofthevinylchloridepeak.The
NOTE 1—There are no similar or equivalent ISO standards covering the
1,2 EDC peak is eluted from the 6-m pre-column and detected
primary subject of this test method.
at the first FID after the two cuts are made.
1.2 This standard does not purport to address all of the
4.2 The components eluting to the two FID detectors are
safety concerns, if any, associated with its use. It is the
identified and quantitated by comparing their retention times
responsibility of the user of this standard to establish appro-
and area counts to those obtained previously from a calibration
priate safety and health practices and determine the applica-
standard run under identical conditions.
bility of regulatory limitations prior to use. Specific hazards
5. Significance and Use
statements are given in Section 8.
5.1 The multidimensional approach permits all of the trace
2. Referenced Documents
impurities to be well separated from the main vinyl chloride
2.1 ASTM Standards:
peak,therebyimprovingquantitativeaccuracyoverestablished
D 883 Terminology Relating to Plastics
packed column methods.
D 1600 Terminology for Abbreviated Terms Relating to
5.2 Theminimumdetectionlimit(MDL)forallcomponents
Plastics
of interest has been shown to be well below 500 ppb for this
F 307 PracticeforSamplingPressurizedGasforGasAnaly-
test method.
sis
6. Apparatus
3. Terminology
6.1 Instrumentation:
3.1 Definitions—Terminology is in accordance with Termi-
6.1.1 HP 5890A (or equivalent), equipped as follows:
nologies D 883 and D 1600 unless otherwise indicated.
6.1.1.1 Split/Splitless Injector System—Must be demon-
strated to be free of discrimination effects induced by vapor
4. Summary of Test Method
viscositydifferencesifhelium-ornitrogen-basedgasstandards
4.1 The liquid vinyl chloride sample or calibration standard
are to be used for instrument calibration.
is injected either directly using a high-pressure liquid sampling
6.1.1.2 Dual Flame-Ionization Detectors.
valveoralternatelyasanexpandedgas.Anappropriatevolume
6.1.1.3 Column Switching Device A pneumatics control
system, available from Scientific Glass Engineering, Inc., or
equivalent.
This test method is under the jurisdiction ofASTM Committee D20 on Plastics
and is the direct responsibility of Subcommittee D20.70 on Analytical Methods.
Current edition approved July 10, 1999. Published October 1999. Originally
published as D 5507 – 94. Last previous edition D 5507 – 94. Available from Hewlett-Packard Co., 3495 Deer Creek Road, Palo Alto,
Annual Book of ASTM Standards, Vol 08.01. California 94304.
3 5
Annual Book of ASTM Standards, Vol 15.03. Scientific Glass Engineering 2007 Kramer Lane, Austin, Texas 78758.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D5507–99
7.4 Liquid CO —Coolant, bone-dry grade, liquid-delivery,
1200-psi helium pad recommended.
7.5 Standards:
7.5.1 Primary Standard—The primary standard is a certi-
fied reference standard, which is blended into a stable nitrogen
or helium matrix. The component concentrations should be
prepared and reported on an as-in-vinyl chloride basis. The
concentrations of the various components in this standard
should also represent typical values expected for the particular
process or sample. The following is a typical calibration
standard composition:
Component Mole, ppm Weight, ppm
Ethylene 29.4 13.2
Propylene 20.0 13.5
Acetylene 6.8 2.8
Butane-1 6.8 6.1
Trans-butene-2 7.1 6.4
Cis-butene-2 7.5 6.7
1,3 butadiene 6.5 5.6
Methyl chloride 36.8 29.7
Vinyl acetylene 12.2 10.2
FIG. 1 Procedure B: On-Line Vaporization Using the LPG
Ethyl chloride 15.9 16.4
1,2 ethylene dichloride 11.8 18.7
Vaporizing Injector
Nitrogen balance
7.5.2 Secondary Standard—The secondary standard is a
6.1.1.4 Sub-Ambient Oven Temperature Control (optional).
vinylchloride-basedblend,whichisusedformethodsetupand
6.1.1.5 LPG Vaporizing Injector, available from Microana-
day-to-day method calibration. This standard is prepared from
lytics Instrumentation, or equivalent (Fig. 1).
actual vinyl chloride product, which is spiked where appropri-
6.2 Data System—Dual HP 3396A Integrators (or equiva-
ate to yield the approximate levels represented in the nitrogen-
lent) permit the acquisition, storage, and reduction of the
based primary standard. The final concentrations should be
output signals from the two FIDs simultaneously. After the
determined by averaging the results from multiple runs, which
initial method development, however, it is possible to consoli-
are referenced to the primary standard. This calibration/
date the output to a single integrator using the instruments
recalibration process may be conducted using an alternate GC
signal switching capability.
procedure.
6.3 Columns:
8. Hazards
6.3.1 Pre-Column—100 cm of 0.20-mm inside diameter
fused silica fixed restrictor coupled to the front ofa6mby
8.1 Appropriate caution must be exercised in handling the
TM
0.53-mm inside diameter GSQ available from J & W
sample due to the suspected carcinogenicity of vinyl chloride.
Scientific (or equivalent).
Any excess of sample beyond that actually injected into the
6.3.2 Analytical Column—9 m by 0.53-mm inside diameter
column should be routed to a purge waste line to be passed to
TM
GSQ available from J&WScientific (or equivalent) plus 25
a vent hood or other suitable disposal location. This excess
TM 8
m by 0.53 mm inside diameter PORAPLOT U Chrompack
sampleincludestheinletsplitterventflowandthesample-loop
(or equivalent).
purge flow in the case in which a gas-valve injection is being
6.4 Syringes—A range of high-quality gas-tight syringes
made.
representing volumes from 0.5 to 25 mL should be available.
9. Sampling
These syringes should be equipped with PTFE-tipped plunger
seals and on and off syringe valves to prevent the loss of gas
9.1 This section is to be followed for all samples, including
sample. unknown samples and the synthetic standards.
9.2 Samples should be supplied to the laboratory in high-
7. Reagents and Materials
pressure sample cylinders, obtained using the procedure de-
scribed in Practice F 307 or similar standards.
7.1 Helium—Carrier gas, zero grade, high quality. Traps
9.3 Placethecylinderinahorizontalpositioninasafeplace
should be placed in the supply lines leading to the gas
such as a hood. Check to see that the container is at least
chromatograph. These traps should reduce oxygen, moisture,
one-half full by opening the valve slightly. The container is at
and hydrocarbons to the lowest possible levels.
least one-half full if liquid is emitted (a white cloud of vapors).
7.2 Hydrogen—Flame gas, high-purity (hydrocarbon free).
Donotanalyzeanysamplesoruseanysyntheticstandardifthe
7.3 Air—Flame gas, high-purity (hydrocarbon free).
liquid in the container is below this amount.
9.4 Placethecylinderinaverticalpositionandrepressureto
1.208 MPa (175 psig) with the chromatographic carrier or
Microanalytics Instrumentation, 2713 Sam Bass Rd., Round Rock, TX 78681.
equivalentinertgasthroughthevalveatthetopofthecylinder,
J & W Scientific, 91 Blue Ravine Road, Folsom, California 95630-4714.
Available from Chrompack Inc., 1130 Route 202, Raritan, NJ 08869. ensuring that no air enters during the operation.
D5507–99
FIG. 3 By-Pass Operation
atmospheric pressure. Repeat the evacuation and filling of the
sample loop with vaporized sample. Turn the valve so that the
FIG. 2 Procedure A: Off-Line Vaporization
vaporized sample is displaced with carrier gas into the chro-
matograph.
9.5.2.2 Procedure B—On-line vaporization using the LPG
9.5 Useeitherofthefollowingtwoproceduresforobtaining
Vaporizing Injector (or equivalent).An alternate approach that
a sample from the container:
has been used successfully for the automated on-line LPG to
9.5.1 Liquid Sample—Connect the cylinder to the liquid
vapor conversion and sample introduction is shown in Fig. 1.
valve on the chromatograph using a minimum length of
The vapor injection occurs in the upper half of this assembly
connecting tubing, so that sample is withdrawn from the
labeled “hot zone.” The automated injection process proceeds
bottom of the cylinder and a liquid sample is obtained. The
as follows:
liquid valve on the chromatograph must be designed in such a
(1) The lower valve of the sample cylinder is opened to
mannerthatfullsamplepressurecanbemaintainedthroughthe
permit the flow of liquid to the fixed restricter (35 to 45-µm
valve without leaking and that means are provided for trapping
pinpoint restriction or equivalent).
a liquid sample in the chromatograph valve under static flow
(2) The constant-pressure force above the liquid drives
conditions. With the exit of the chromatograph valve closed,
liquid across the fixed restrictor at a constant rate.
open the valve on the cylinder. Open the exit from the
(3) The vapor formed in the heated vaporizer tube is mixed
chromatograph valve slowly so that liquid flows through the
prior to passing through the block out valve and on through the
connecting line and valve. Close the exits so that the liquid
sample loop to vent.
sample is trapped in the valve. Perform the necessary opera-
(4) The sample loop purge is permitted to proceed for a
tions to introduce the liquid sample into the chromatograph
fixedperiodoftimethatissufficienttoensureacompletepurge
column.
of the loop volume.
9.5.2 Vaporized Sample:
(5) The block out valve automatically shuts off the flow of
9.5.2.1 Procedure A—Off-Line Vaporization:
vapor to the sample loop after the sample-loop purge period.
(1) Assemble the apparatus in a manner similar to that
(6) Ashort delay period is permitted after sample block out
illustratedinFig.2.Disconnectthe1700-cm cylinderatEand
andbeforesampleinjection.Thisdelayensuresthatthesample
evacuate. Close Valve B and open Valves C and D, allowing
the liquid sample to flow into the small cylinder. OpenValve B loop is permitted to decay back to atmospheric pressure.
slowlyandallowthesampletoflowthroughuntilasteadyslow (7) The gas sampling valve is then actuated to inject the
stream of liquid emerges from B. Close Valves B, C, and D in sample loop contents into the flowing carrier gas stream and
that order, trapping a portion of the liquid sample in the pipe simultaneously begin the GC run.
cylinder. Attach the evacuated cylinder (1700-cm volume) at
E. Open Valve A and then Valve B. The liquid will expand, 10. Preparation of Apparatus
filling the larger cylinder. Close Valve A and disconnect at E.
10.1 The column/transfer tube combination is installed as
outlined in the schematic shown in Fig. 3 (by-pass operation)
NOTE 2—To prevent possible rupture of the liquid-filled pipe cylinder,
the sample cylinder and its contents should be at room temperature prior and Fig. 4 (heart-cut operation).
to sampling, and the liquid should be allowed to remain in the pipe
10.2 Initial Instrument Parameters:
cylinder for only a minimum of time.
10.2.1 Columns:
(2) Connect the cylinder containing the vaporized sample to 10.2.1.1 Pre-Column—100 cm of 0.20-mm inside diameter
thechromatographgasvalve.Evacuatethesampleloopandthe fused silica fixed restrictor coupled to the front ofa6mby
TM
lines up to the sample cylinder. Close the valve to the vacuum 0.53-mm inside diameter GCQ available from J & W
source and allow the sample loop to fill with sample up to Scientific (or equivalent).
D5507–99
10.3.4 The mid-point pressure is increased slightly after
each such injection until the pressure differential is reached, at
which the test peak is absent (or acceptably small) from the
second detector. This is the correct pressure differential for
normal heart-cut and back flush operations.
10.3.5 This pressure tuning process should be required only
once for any combination of columns and restrictors.
10.4 Establishing Column Switching Parameters—The
heart-cut and cold-trap times in the instrument parameters (see
10.2) can be used as a general guideline or can be developed
from the following procedure:
10.4.1 The process of establishing the heart-cut times for
this procedure is begun by determining retention times for the
pre-column separation only. This is accomplished by holding
the system in the monitor mode while the first complete run is
FIG. 4 Heart-Cut Operation
made with the secondary standard. A sample volume of 1.0 to
1.25 mL should be used for this and all subsequent injections.
10.2.1.2 Analytical Column—9 m by 0.53-mm inside diam-
10.4.2 The retention times from this first run are then used
TM
eter GSQ plus 25 m by 0.53 mm inside diameter PORA-
to determine the approximate start and stop times required for
TM
PLOT U (Chrompack).
heart-cut No. 1. This cut should include all of the trace
10.2.2 Injection Mode—Split.
impurities, which elute prior to the vinyl chloride peak (that is,
10.2.3 Split Ratio—At 1:1.
ethane, ethylene, acetylene, propylene, and methyl chloride).
10.2.4 Split Volume—At 15 mL/min.
The best results are achieved in practice if the first cut is
10.2.5 Injection Volume—At 1.00 mL.
terminated just into the front edge of the large vinyl chloride
10.2.6 Injection Temperature—180°C.
peak.
10.2.7 Detector Temperature—240°C.
10.4.3 After the times are finaliz
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