Rapid Screening and Simultaneous Confirmation of 64 Pesticide Residues in Vegetable Using Solid Phase Extraction-comprehensive Two-dimensional Gas Chromatography Coupled with Time-of-Flight Mass Spectrometer

A solid phase extraction-comprehensive two-dimensional gas chromatography coupled with time-of-flight mass Spectrometric (GC X GC-TOF-MS) method for analysis of 64 pesticides in vegetables was developed and validated. After extracting with acetonitrile, cleaning-up with NH2-SPE cartiidge and concentrating with nitrogen, the pesticide residues were redissolved in the acetone and analyzed by GC X GC-TOF-MS coupled with HP-5MS and column DB-17 column. Sample matrix-matched calibration was used to determine the residue contents by external standard. The method was validated by the real samples, such as Brassica campestris, cucumber, eggplant, kidney bean and capsicum. The limits of detection (S/N= 3) and the limits of quantification (S/N= 10) were from 0. 010 to 6. 032 mu g/kg and from 0. 035 to 20. 107 mu g/kg, respectively. The overall recoveries ranged from 68.3% to 117.8% with the relative standard deviations (RSD) of 0. 6%-9. 1%. Two positive samples, polluted by acephate and cypermethrin with a residual concentration of 0. 036 and 0. 107 mg/kg, were screened by the developed method as detecting markets samples.