Determinação multirresíduo de agrotóxicos em aveia empregando cromatografia líquida acoplada à espectrometria de massas em série

Abstract

Many pesticides are used for pest control during oat production and storage, making necessary to employ multi-class methods for pesticide residues determination. For this purpose, the QuEChERS method allows adequate sample preparation and, coupled with liquid chromatography with tandem mass spectrometry (LC-MS/MS), allows the multiresidue determination of a large number of pesticides at low levels. In this work, different sorbents, such as chitosan, Forisil®, C18, PSA, Supel QuE Z-Sep+ and EMR-Lipid were evaluated for clean-up efficiency of the extract by dispersive solid phase extraction. The original QuEChERS method had the best performance and the biosorbent chitosan presented similar results to the other conventional sorbents evaluated and being an efficient and low cost biodegradable sorbent was chosen for the clean-up step. The proposed method presented adequate accuracy and precision, with recovery between 70 and 120 % and RSD <20%, for the determination of residues of 60 pesticides in oats by LC-MS/MS. The method limits of quantification ranged from 5 to 100 μg kg-1. The method was successfully applied in real samples and is an appropriate option for routine analysis.