HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC DETERMINATION OF MIGRATING POLY(ETHYLENE-TEREPHTHALATE) OLIGOMERS IN CORN-OIL

A high-performance liquid chromatographic (HPLC) method has been developed for determining poly(ethylene terephthalate) (PET) oligomers in corn oil. The oligomers are extracted from corn oil with hexane-acetonitrile, the extract is evaporated almost to dryness, and the concentrate is diluted with dimethylacetamide for separation and quantitation of the oligomers by HPLC. Recovery studies were performed using bis(2-hydroxyethyl) terephthalate (BHET) and the PET cyclic trimer. The mean recoveries from corn oil were 96. 2 and 98. 4% for BHET and the PET cyclic trimer, respectively. This method was also used to measure the migration of PET cyclic oligomers from PET susceptor food trays, PET-coated paperboard food trays, and crystallized PET food trays under microwave-use conditions. Oligomers beginning with the cyclic trimer through the cyclic octamer were found to migrate. © 1990, American Chemical Society. All rights reserved.