Abstract: Buprofezin and triadimefon residues in cucumbers were determined by gas chromatography-mass spectrometry (GC- MS) with electron impact (EI) ionization. The samples were treated by extraction solvent aceton and petroleum ether, then dichloromethane.The organic phase was separated from water by adding NaCl. No clean up step was required. Buprofezin and triadimefon were analyzed by GC-MS with selected-ion monitoring (SIM). Detection limits of 2 pesticides were 0.13 and 0.013 mg/ kg. The recoveries of 2 pesticides ranged from 71.7% ～ 123%. The relative standard deviation was 6.5%～17%.

Key words: gas chromatography-mass spectrometry, buprofezin, triadimefon, pesticide residues, cucumber, selected-ion monitoring