Measuring trace amounts of residual monomers in a synthetic polymer by gas-liquid chromatography (GLC) has been used for over a quarter century [1-3]. A recent review of gas chromatography (GC) polymer analysis has shown it to be useful for monitoring devolatilisation of unreacted monomers and solvent residues, particularly when they are an environmental hazard. Other reasons for analysis include: establishing the experimental conditions for polymer formation, and overall control of odour [4].

There are several injection methods currently used in GC monomer determinations. However, all of these techniques fall into two categories: direct injection and injection of the vapour above the polymer, i.e., headspace analysis or polymer solution. Direct injection of a polymer, or its precipitates, is perhaps the most common method. This technique requires both an inert material in the injection port to trap the polymer, and a narrow window of acceptance on the injection port temperature. High temperatures lead to polymer decomposition while low temperatures prevent fast volatilisation of the monomer. In addition, the sample viscosity must be low enough to allow handling with a syringe.

There has been a great amount of recent interest in GLC separation of monomers in polymeric matrices. A direct injection approach has been reported, in which a copolymer was precipitated with concentrated acids and subsequently extracted with an organic solvent. This method avoids polymerisation of the monomer in the injection port, as well as permitting use of low-viscosity (aqueous) solvents. Other approaches include extractive distillation prior to separation, using either packed column...