Determination of volatile and semi-volatile model contaminants in recycledhigh-impact polystyrene from food-contact applications. Comparison of extraction by purge-and-trap, co-evaporation, and total dissolution

Seven samples of high-impact polystyrene (HIPS) flakes, from post-consumer coffee cups, previously deliberately contaminated with four volatile and se mivolatile model compounds(1,1,1-trichloroethane, methylbenzene, chlorobenz ene, and phenylcyclohexane) to simulate misuse, have been collected at diff erent times from a recycling plant and analyzed directly after extraction b y purge-and-trap or by co-evaporation (a modified static headspace procedur e). As a reference method HIPS samples were also dissolved in dimethylacetamide (to furnish an homogeneous matrix) and analyzed after extraction by coevap oration. Significance tests were used to evaluate the feasibility of using these methods for the direct analysis of solid polymers. Results obtained b y use of the three methods are compared and discussed.