01/22/2010

Approach by Gas Chromatography-Quadrupole-Mass Spectrometry for Pesticide Residues in Fruits and Vegetables



A full-scan GC/quadrupole/MS method has been developed to perform large-scale screenings of pesticides and simultaneous quantification of 95 target compounds in a single run of 21 min. The screening method was performed by using a deconvolution of the spectrum of the full-scan data files acquired under a retention time locked method.

The identification performance of the screening method was evaluated in eight different food matrixes at three different concentrations. The system was equipped with a programmable temperature vaporizing inlet, allowing 10 mLinjections. The LOQ in the full-scan mode and linearity were studied for four different matrixes.

Correlation coefficients >0.99 were achieved in all cases, and the LOD was <20 mg/kg for 80% of the studied pesticides. Maintenance of the system was reduced by the use of a QuickSwap device that provided backflush capabilities by reversing column flow immediately after elution of the last compound of interest. The combined screening and target method was used in the analysis of more than 100 food samples, including a carrot sample fromthe European Proficiency Test FV 10, with good results.

Full Article: JOURNAL OF AOAC INTERNATIONAL VOL. 92, NO. 6, 2009

Source: Community Reference Laboratories for Residues of Pesticides