Migration from polycarbonate packaging to food simulants during microwave heating

The interactions between polycarbonate (PC) packaging and different food simulants during microwave heating were evaluated by identifying the compounds migrating into aqueous, alcoholic and fatty food simulants. The migration of compounds, such as 9,9-dimethylxanthene and m-tert-butyl-phenol, from the PC package to ethanol and isooctane increased significantly during microwave heating as compared to conventional heating. The increase in migration can be explained by degradation caused by microwave heating and/or stronger food simulant interactions. Depending on the food simulant the migrants were quantified either by multiple headspace - solid-phase micro-extraction (MHS-SPME) or direct injection in combination with gas chromatography-mass spectrometry. A partial least squares (PLS) regression model was developed to predict the extraction efficiency for headspace - solid-phase micro-extraction (HS-SPME) of food package migrants from the analyte properties. The most significant property for prediction of the enrichment factors was the octanol-water partition coefficient (log Kow). Polydimethylsiloxane (PDMS) and polydimethylsiloxane/divinylbenzene (PDMS/DVB) fibres were compared for the extraction of the migrants. High correlation was found between the PDMS and PDMS/DVB enrichment factors (R2 = 0.98), but the extraction by PDMS/DVB fibre was much more efficient compared to the extraction by PDMS fibre. The detection limits after SPME extraction by PDMS/DVB fibre were 1, 0.1 and 3 ng/L for 4-ethoxy-ethyl-benzoate, 2,4-di-tert-butyl-phenol and benzophenone, respectively.