ASTM D4526-96

For various reasons, one may want to measure the level of unreacted or residual monomer, water, or other volatile components in a polymer sample.

Volatiles of interest are often at trace concentrations. Headspace analysis is suited for determination of these trace components which often cannot be determined by conventional gas chromatography because of sample decomposition or interferences.

For polymer analysis, sample treatment for headspace analysis is simpler than conventional gas chromatography, where precipitation steps may be required to prevent polymer contamination of the chromatographic column.

This headspace practice will be able to determine qualitatively any component with sufficient vapor pressure. It is capable of yielding semiquantitative results and can be used for relative comparisons between samples.

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.

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. Specific precautionary statements are given in Section 6.

Note 1--There is no equivalent ISO standard.