Semiqualitative Method for Detection of Pesticide Residues Over Established Limits in Vegetables by Use of GC–μECD and GC–(EI)MS

A new method is presented for the rapid classification of vegetable samples into negatives and non-negatives depending on their pesticide residue content. The method uses intervals developed during qualitative method validation to accurately distinguish between both types of sample, minimizing the possibility of releasing false positive and false negative results. It also enables a large number of samples to be processed simply and reliably. The method, which includes twenty pesticides including pyrethroids, and organophosphorus and organochlorine compounds, has been applied to two different vegetables (peppers and green beans). Recoveries are acceptable in all instances and limits of detection (LOD) are always below regulatory limits. Full-scan GC–(EI)MS is used to change the non-negative conclusion into either positive or negative by following typical confirmation procedures found in the literature.