Abstract: A method for the simultaneous determination of 23 phthalate esters in food samples by solid-phase extraction coupled with gas chromatography-mass spectrometry (SPE-GC-MS) was developed and evaluated. The samples were extracted with hexane or acetonitrile, and cleaned up with a glass ProElut PSA SPE column. The identification and quantification were performed by GC-MS in selected ion monitoring (SIM) mode. The extraction processes of different foods were investigated. The calibration curves of phthalate esters showed good linearity in the range of 0.05~5 mg/L (0.5~5 mg/L for diisononyl phthalate (DINP), diisodecyl-phthalate (DIDP)) with the correlation coefficients (r) between 0.9848 and 0.9996. The limits of detection of phthalate esters in food samples ranged from 0.005 to 0.05 mg/kg (S/N=3) and the limits of quantification ranged from 0.02 to 0.2 mg/kg (S/N=10). The average recoveries of 23 analytes spiked in 10 kinds of food matrices ranged from 77% to 112% with the relative standard deviations (RSDs, n=6) of 4.1%~12.5%. The method is suitable for the determination of 23 phthalate esters simultaneously in foodstuffs with easy operation, high accuracy and precision.

Key words: gas chromatography-mass spectrometry (GC-MS), foods, phthalate esters (PAEs), plasticizer, solid-phase extraction (SPE)