A method for polymeric analysis based on pyrolysis followed by gas chromatography/mass spectrometry has been developed using high resolution, capillary gas chromatography directly interfaced to a double-focussing mass spectrometer. Introduction of samples using the pyrolysis carrier gas of choice through the split injection port followed by sub-ambient focussing of the pyrolysis products gave reproducible chromatograms. 7 refs., 8 figs.