Identification of pesticide residues in common fruits and vegetables by gas chromatography-quadrupole time-of-flight mass spectrometry

Abstract

A new screening method was developed for the determination of 152 pesticide multiresidues in different chemical species with a Carbon NH2 column using solid-phase extraction (SPE) coupled with gas chromatography-quadrupole time-of-flight mass spectrometry (GC-QTOF MS). In the first stage (MS1) accurate mass database, up to three-five ions of the pesticides were monitored. The presence of at least three ions and the accomplishment of the intensity ratio (Q/qi) within the established tolerances were used as the confirmation of intensity criteria. The pesticides which have less characteristic ions or the peaks of the characteristic ions detected were up the tolerance were determined in the second stage (MS2) and the spectral difference was evaluated using MS2 library for the identified. Cabbage, tomato, pear were selected as typical fruits and vegetables to spike and detected all the 152 pesticides at two concentration levels of 5.0 and 10.0 μg/kg. The recoveries in the range of 70% -120% at two concentration levels were 91.A5% and 94.08% for cabbage, 88.20% and 88.80% for tomato, 86.84% and 92.10% for pear respectively. Using the established 152 pesticide MS2 library some suspected pesticides were identified, and at the same time the analysis scope was expanded.