APPLICATION OF HEADSPACE GAS CHROMATOGRAPHY TO ANALYSIS OF RESIDUAL VOLATILES IN SYNTHETIC RUBBERS.

For many years the conventional analytical technique for measuring residual monomers, solvents, and other small molecule impurities in rubber has been gas chromatography (GC). The sample was dissolved in a suitable solvent and chromatographed. However, the analytical requirements in the last couple years have dictated lower levels of detection than are possible with the solution method using flame ionization detection. A recent paper described a modified solution approach combined with headspace GC. This paper describes various aspects of headspace gas chromatography as a general method for direct measurement on solid rubber samples for trace levels of residual volatiles. The advantages of headpsace sampling are numerous and this technique has enabled the authors to obtain reliable quantitative data by gas chromatography on residual volatiles, particularly higher boiling compounds, that could not be measured only a couple years ago.