Abstract: A method was established for the determination of bifenthrin residue in 8 plant-based foods using gas chromatography-mass spectrometry （GC-MS）. The grain was extracted by acetonitrile and cleaned up with gel permeation chromatography （GPC） combined with a Florisil solid-phase extraction （SPE） cartridge, while the vegetables and fruits were extracted by ethyl acetate and cleaned up only with a Florisil SPE cartridge. Most of the lipids in the extract for the grain were eliminated by GPC, prior to SPE cleanup. The cleaned extract was analyzed by GC-MS with electron impact (EI) source in selective ion monitoring (SIM) mode. The detection limit was 5 μg/kg （S/N=10）. There was a good linearity within the range of 0.005-0.5 mg/L with the correlation coefficient of 0.9999. The recoveries were between 74%-99% with the relative standard derivations of less than 13% at the spiking levels of 0.005, 0.04 and 0.1 mg/kg

Key words: bifenthrin, gas chromatography-mass spectrometry (GC-MS), plant-based foods , solid-phase extraction (SPE), gel permeation chromatography （GPC）