Analysis of 136 pesticides in avocado using a modified QuEChERS method with LC-MS/MS and GC-MS/MS.

A simple and high-throughput screening method for the analysis of 136 pesticides in avocado ( Persea americana ) by LC-(+)-ESI-MS/MS and GC-MS/MS is presented. A modified QuEChERS sample preparation method was developed to improve the extraction recovery of highly lipophilic pesticides. Extracts from minced avocados after acetonitrile (MeCN) extraction were directly injected to LC-MS/MS, whereas other GC-amenable compounds were treated with the modified QuEChERS procedure for GC-MS/MS analysis.