Pyrolysis-gas chromatography-mass spectrometry of a series of bile acid sequestrants

Pyrolysis of a series of polymers based on polystyrene and used as bile acid sequestrants produced characteristic mixtures of compounds which were analysed by gas chromatography-mass spectrometry. The nature of the substituent groups was clearly apparent while the polymer backbone gave rise to representative styrenes. The reproducibility of the results was examined by experimenting with the temperature of pyrolysis. It was found that at low temperatures very little fragmentation of the polystyrene backbone occurred but the substituents were still released in high yield. The orientation of the various substituted styrenes generated by pyrolysis was confirmed by the use of gas chromatography with infrared and mass spectrometric detection.