Abstract:  A multiresidue analytical method for rapid screening of 176 pesticide residues in vegetables was developed by using ultra fast liquid chromatography-tandem mass spectrometry (UFLC-MS/MS). The vegetable samples were extracted by acetonitrile. It is not necessary for the extract to make a further purification after salting out. Multiple reaction monitoring with information-dependent acquisition of enhanced product ion (MRM-IDA-EPI) was used for the analysis. Based on EPI spectra and chromatographic peak area, identification and quantification of the 176 pesticide residues in vegetables were carried out by using library search technique. All the pesticides had the good linearity within their respective linear ranges (r＞0.99). The average recoveries of the 174 pesticides except for carbosulfan and cyromazine were in the range of 72.4% to 126.4% with the relative standard deviations (RSDs) from 1.0% to 18.7%. The limits of detection and quantification of the method were 0.005-2.0 μg/kg and 0.1-10 μg/kg, respectively. The results demonstrated that the method has distinct advantages of rapid speed, high sensitivity and good accuracy. Therefore, this method is suitable for the rapid screening of pesticide residues in vegetables.

Key words: library search, pesticide residues, screening, vegetables, ultra fast liquid chromatography-tandem mass spectrometry (UFLC-MS/MS)