Simultaneous determination of 17 phthalate esters in edible vegetable oils by GC-MS with silica/PSA-mixed solid-phase extraction.

A quantified method for the determination of 17 phthalate esters (PAEs) in edible vegetable oil by GC-MS with the pretreatment of acetonitrile extraction and silica/N-(n-Propyl)ethylenediamine-mixed SPE column was established. By the quantification of internal standard of D(4)-di(2-ethylhexyl) phthalate, a good linearity range of related 17 PAEs was observed. The correlation coefficient was ranged at 0.994~1.000, and the standard lowest quantified level was 0.05~0.15 mg/L. The spiking recoveries of 17 PAEs were 78.3~108.9% with the relative standard deviations of 4.3~12.1% (n = 6). The method detection limits were 0.1~0.2 mg/kg. Meanwhile, PAEs were determined in 30 plastic buckets of edible vegetable oil from supermarkets in Hangzhou city of China. The survey of 30 oil samples showed di(2-ethylhexyl) phthalate (DEHP) had the 100% (30/30) detection rate. The levels of diisobutyl phthalate with 86.7% (26:30), di-n-butyl phthalate (DBP) with 70% (21:30) and diethyl phthalate with 10% (3:30) were detected. It was worth note that DBP with 16.7% (5:30) samples and DEHP with 10% (3:30) samples were beyond the regular migrating limit, which indicated that more attention should be paid to the PAEs in oil with plastic package.