Migration of Ethylene Terephthalate Oligomers from Roasting Bags into Olive Oil

Abstract

A high-performance liquid-chromatographic method with UV detection (HPLC–UV) has been developed for quantification of ethylene terephthalate oligomers in olive oil, from which they were extracted with acetonitrile. Oligomers, from monomers (M1) to pentamers (M5), were jointly and/or individually identified by liquid chromatography with mass spectrometry (electron-impact mass spectrometry (EIMS) low- and high-resolution) and were quantified by HPLC–UV using an acetonitrile solution of the major oligomer (the trimer M3) as standard. For M3 recovery was 98.9%, the detection limit was 60 μg L−2, and method precision was 2.03% (RSD). Migration of oligomers M1–M5 into 50 mL olive oil sealed in each of two brands of 10 cm × 10 cm poly(ethylene terephthalate) roasting bag was evaluated under two sets of conditions that approached but remained below the limit at which the bag material became physically deformed – heating for 7 min at 850 W in a microwave oven, or for 60 min at 200 °C in a conventional oven. Total migration was approximately 2.7 mg dm−2 under the former conditions and 3.5–4.1 mg dm−2 under the latter.