Abstract:

A novel and rapid method based on high performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed for determination of organophosphorus pesticide residues (OPs) in tobacco. The OPs were extracted from tobacco samples by acetonitrile under ultrasonication. The extractive was determined by high performance liquid chromatography using methanol-water (containing 0.1% ammonium acetate) (95∶5, v/v) as mobile phase. The OPs were detected using a tandem mass spectrometer with electrospray ionization in multiple reaction monitoring (MRM) mode. The OPs, such as dimethoate, trichlorfon, chlorpyrifos, methamidophos and acephate could be detected quantitatively within 2.5 min. The linear calibration curves were obtained in the entire range (1-200 μg/L) for all the above pesticides (r＞0.998). The average recoveries in tobacco obtained were ranged from 77% to 104%. The limits of detection were between 1.0 μg/kg and 5.0 μg/kg.

Key words: multiple reaction monitoring, organophosphorus pesticide residues (OPs), tobacco , liquid chromatography-tandem mass spectrometry (LC-MS/MS)