Abstract: An analytical method for the rapid determination of 50 pesticides residues in citrus by gas chromatography-mass spectrometry (GC-MS) with QuEChERS was established in a selected ion-monitoring (SIM) mode. The pesticide residues in samples were extracted into acetonitrile and salted out by anhydrous MgSO4 and NaCl. Then, the pesticide residues in the supernatant after clean-up on N-propyl ethylenediamine (PSA) cartridge were subjected to GC-MS analysis. Under the optimal conditions, the limits of detection (RSN ＝ 3) of the established method were in the range of 0.0038－0.066 mg/kg, and the average recovery rates (ｎ＝6) for 50 pesticide residues in a blank sample were 72.0%－118.2% with a relative standard deviations (RSDs) of 1.7%－19.7%.

Key words: citrus, QuEchERS, gas chromatography-mass spectrometry (GC-MS), multiple pesticide residue analysis