A fast and easy GC-MS/MS method for simultaneous analysis of 73 pesticide residues in vegetables and fruits

A simple and easy method was established for the simultaneous determination of 73 pesticide residues in vegetables and fruits by gas chromatography-tandem mass spectrometry (GC-MS/MS). After samples were ultrasonically extracted with hexane and centrifuged, the analytes in sample solution were separated with DB-5MS column (30 m x 0.25 mm, 0.25 mu m). Qualitative determination of the analytes was based on characteristic ion pairs and retention time using multiple reactions monitoring (MRM) mode. The mixed-matrices standard curves were used for quantification. The calibration curves were mostly in the range of 10-1000 mu g L-1. The limits of detection (LODs) of the method were from 0.012 to 18.8 mu g kg(-1) and limits of quantification (LOQs) were in the range of 0.042-61.8 mu g kg(-1), which were much lower than the maximum residue levels (MRLs) established by European legislation. The average recoveries of the method ranged from 86.7% to 124%, 85.6% to 117%, 89.2% to 111% at three spiked levels of 0.10, 0.20, 0.50 mg kg(-1) in leek samples, with relative standard deviations (RSDs) of 1.84% to 11.3%, 2.40% to 9.50%, 0.79% to 8.30%, respectively. Additionally, the method was more favorable than gas chromatography-mass spectrometry (GC-MS) in the analysis of 15 spiked samples, including ten vegetables and five fruits. Three pesticides were detected in the samples of celery and apple by the established method and the GC-MS method.