ASTM D4526-96(2007)
(Practice)Standard Practice for Determination of Volatiles in Polymers by Static Headspace Gas Chromatography
Standard Practice for Determination of Volatiles in Polymers by Static Headspace Gas Chromatography
SCOPE
1.1 Headspace gas chromatography (GC) involves the determination of volatile components in a polymer solution by gas chromatography of a vapor phase in thermal equilibrium with the sample matrix. Volatiles in finely ground insoluble polymers can also be determined with and without an extracting solvent.
1.2 This practice provides two procedures:
1.2.1 Procedure A - Automatic headspace analysis.
1.2.2 Procedure B - Manual injection headspace analysis.
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 precautionary statements are given in Section 6.Note 1
There is no equivalent ISO standard.
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: D4526 − 96(Reapproved 2007)
Standard Practice for
Determination of Volatiles in Polymers by Static Headspace
Gas Chromatography
This standard is issued under the fixed designation D4526; 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* 3. Significance and Use
3.1 For various reasons, one may want to measure the level
1.1 Headspace gas chromatography (GC) involves the de-
of unreacted or residual monomer, water, or other volatile
termination of volatile components in a polymer solution by
components in a polymer sample.
gas chromatography of a vapor phase in thermal equilibrium
with the sample matrix. Volatiles in finely ground insoluble
3.2 Volatiles of interest are often at trace concentrations.
polymers can also be determined with and without an extract- Headspace analysis is suited for determination of these trace
ing solvent. componentswhichoftencannotbedeterminedbyconventional
gas chromatography because of sample decomposition or
1.2 This practice provides two procedures:
interferences.
1.2.1 Procedure A—Automatic headspace analysis.
3.3 For polymer analysis, sample treatment for headspace
1.2.2 Procedure B—Manual injection headspace analysis.
analysis is simpler than conventional gas chromatography,
where precipitation steps may be required to prevent polymer
1.3 This standard does not purport to address all of the
contamination of the chromatographic column.
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
3.4 This headspace practice will be able to determine
priate safety and health practices and determine the applica-
qualitatively any component with sufficient vapor pressure. It
bility of regulatory limitations prior to use. Specific precau-
is capable of yielding semiquantitative results and can be used
tionary statements are given in Section 6.
for relative comparisons between samples.
NOTE 1—There is no equivalent ISO standard.
4. Apparatus
4.1 Gas Chromatograph, equipped with an appropriate
2. Referenced Documents
detector and backflush valve.
2.1 ASTM Standards:
4.1.1 For Procedure A, an Automated Headspace Sampler,
4,5
D4322Test Method for Residual Acrylonitrile Monomer
including backflush capability, thermostated sample tray,
Styrene-Acrylonitrile Copolymers and Nitrile Rubber by
and associated accessories fulfill these requirements while
Headspace Gas Chromatography (Withdrawn 2010) providing for automatic sequential sampling of headspace
E260Practice for Packed Column Gas Chromatography
vapors.
E355PracticeforGasChromatographyTermsandRelation- 4.1.2 Procedure B requires the following additional equip-
ment:
ships
4.1.2.1 Constant-Temperature Bath, capable of maintaining
E594Practice for Testing Flame Ionization Detectors Used
90 6 1°C.
in Gas or Supercritical Fluid Chromatography
4.1.2.2 Gas-Tight Gas Chromatographic Syringes, which
can be heated to 90°C for sampling and injection.
4.1.2.3 Valve, 6-port for backflush assembly.
ThispracticeisunderthejurisdictionofASTMCommitteeD20onPlasticsand
is the direct responsibility of Subcommittee D20.70 on Analytical Methods.
NOTE 2—Appropriate detectors could include the following:
Current edition approved Sept. 1, 2007. Published November 2007. Originally
(a) Flame ionization (FID) for general organic volatiles,
´1
approved in 1985. Last previous edition approved in 2001 as D4526-97(2001) .
DOI: 10.1520/D4526-96R07.
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 Thesolesourceofsupplyoftheapparatusknowntothecommitteeatthistime
Standards volume information, refer to the standard’s Document Summary page on is Perkin-Elmer Corp., Main Ave., Norwalk, CT 06856.
the ASTM website. If you are aware of alternative suppliers, please provide this information to
The last approved version of this historical standard is referenced on ASTM International Headquarters. Your comments will receive careful consider-
www.astm.org. ation at a meeting of the responsible technical committee, which you may attend.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D4526 − 96 (2007)
(b) Electron capture (EC) for halogenated species,
6. Safety Precautions
(c) Nitrogen-phosphorous (NPD) for acrylonitrile,
6.1 Volatiles such as vinyl chloride and acrylonitrile should
(d) Thermal conductivity (TC) for water, and
notbereleasedtothelaboratoryatmosphere.Preparestandards
(e) Hall electroconductivity or photoionization (PID) for vinyl chlo-
ride.
and handle samples in a well-ventilated fume hood.
4.2 Chromatographic Columns:
6.2 Some of the recommended solvents are flammable.
5,6
Dimethylacetamide is also absorbed through the skin, so avoid
4.2.1 Packed Column Analysis—Column packings found
contact.
to be useful for residual monomers (for example, acrylonitrile,
vinyl chloride) include Chromosorb or Porapak porous poly-
6.3 Be careful not to come into contact with heated chro-
merpackings,0.4%Carbowax1500liquidphaseonCarbopak
matograph parts, such as the detector, column, rotating sample
Csupport,or0.19%picricacidonCarbopakCsupport.Other
tray, hot sample bottles, etc.
columns can be used after it is determined that they give the
6.4 Once heated, sample vials containing polymer volatiles
requiredresolutionandaccuracyforthecomponentofinterest.
are under pressure. After analysis, vent the pressure with a
4.2.2 Capillary Column Analysis—Choose a column ca-
hypodermic syringe needle connected to a charcoal slug or
pable of achieving the required resolution for the components
vented hood before removing vials from the constant tempera-
ofinterest.Forexample,foracrylonitrilemonomer,thecolumn
ture bath.
of choice is a Quadrex 007–2, 25m × 0.32–mm internal
5,7
diameter fused silica.
7. Storage and Sampling
4.3 Integrator, recorder (5–mV full scale), computing inte-
7.1 To prevent loss of volatiles from polymer pellets, or
grator or appropriate computer data station and software
resin, store in tightly sealed jars with minimal headspace or
capable of measuring and storing peak area data.
heat-sealed pouches constructed of an outer polyester layer, an
aluminum foil middle layer, and a polyolefin inner sealing
4.4 Headspace Vials, septa, ring closures, and vial sealer.
layer.
4.5 Analytical Balance, capable of weighing to 60.0001 g.
7.2 Forrolledpolymerfilmsamples,discard3to5moffilm
4.6 Soap Film Flowmeter and Stopwatch,orothermeansof before taking the sample for headspace analysis because
volatiles can be lost by diffusion through the outer film layers.
measuring gas flow rates.
7.3 Powdered resin samples (for example, poly(vinyl chlo-
4.7 Pressure Regulators for all required gas cylinders.
ride)) can be weighed directly into a tared headspace vial. A
4.8 Filter-Dryer Assemblies
...
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