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 D4-di(2-ethylhexyl) phthalate, a good linearity range of related 17 PAEs was observed. The correlation coefficient was ranged at 0.994 similar to 1.000, and the standard lowest quantified level was 0.05 similar to 0.15 mg/L. The spiking recoveries of 17 PAEs were 78.3 similar to 108.9% with the relative standard deviations of 4.3 similar to 12.1% (n = 6). The method detection limits were 0.1 similar to 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.