A method for the determination of 16phthalates in diet samples was developed by isotope-dilution gas chromatography-mass spectrometry with gel permeation chromatography cleanup.MethodsSamples with isotope internal standard solutions were ultrasonically extracted by cyclohexane-saturated acetonitrile and followed by gel permeation chromatography (GPC) cleanup. The components were separated on a DB-5ms capillary column(30m×0.25mm,0.25mm)by GC-MS under selected ion monitoring (SIM) mode,and quantified by the isotope internal standards．ResultsThe average recoveries of the spiked diet samples were in the range of 52.3%-124.7% with the relative standard deviations in the range of 1.6%-16.2%. The limits of detection (LODs) were 0.03-0.06μg/kg.ConclusionThe method is suitable for the determination of 16phthalate esters simultaneously in diet samples with easy operation,high accuracy and precision．