Determination of 127 Pesticide Residues in Cucumber,Flowering Cabbage,Grape and Banana by QuEChERS Method Coupled with High Performance Liquid Chromatography Tandem Mass Spectrometry

A rapid method was developed for the simultaneous determination of 127 pesticide residues belonging to different chemical classes in cucumber,flowering cabbage,grape and banana by high performance liquid chromatography tandem mass spectrometry( HPLC-MS / MS). The samples was prepared by the modified Qu ECh ERS( quick,easy,cheap,effective,rugged and safe) method,extracted with acetonitrile containing 1% acetic acid,salted out with anhydrous magnesium sulphate and anhydrous sodium acetate,and cleaned-up by adding primary secondary amine( PSA) and graphitized carbon black( GCB). The 127 target compounds were separated on an Ultra AQ C18( 100 mm× 2. 1 mm,3 μm) column using 5 mmol / L ammonium formate methanol solution and 5 mmol / L ammonium formate as mobile phase by gradient elution at a flow rate of 0. 4 m L / min in 15 min,and analyzed by positive electrospray ionization tandem mass spectrometry under multiple reaction monitoring( MRM) mode. The external standard method was used for quantitative analysis. The calibration curves of 127 pesticide residues were linear in the range of 0. 50-40. 0 μg / L with correlation coefficients( r) more than 0. 99. The recoveries at spiked levels of 10,20,50 μg / kg for all target compounds in the samples were in the range of 60. 0%-118. 5%,with relative standard deviations of1. 2%-21. 9%. The limits of quantitation( LOQs,S / N≥10) were not more than 8. 9 μg / kg. The method was simple,rapid,sensitive and reliable,and could be used in the screening and determination of 127 pesticide residues in fruits and vegetables.