Determinação de resíduos de avermectinas em leite bovino empregando QuEChERS modificado e UHPLC-MS/MS

Abstract

In Brazil, agro-industry is one of the most important economic sectors. However, there is a need for improved and more efficient quality control techniques in some areas, including the milk sector. This study employed an adapted acetate QuEChERS method, with a clean-up step using C18, MgSO4, PSA for UHPLC-MS/MS determination of avermectin residues in bovine milk. Five avermectins were analyzed: abamectin, ivermectin doramectin, emamectin, doramectin and eprinomectin. The blank samples were spiked at 0.5, 1 and 1.5 x the Maximum Residues Limit (MRL) for each compound. The evaluated validation parameters were: linearity, precision, selectivity, accuracy, limit of detection (LOD) and of quantification (LOQ) and matrix effect. The method presented good LOD (1.5, 2.25 and 3 μg L-1) and LOQ values (5, 7.5, and 10 μg L-1). Recoveries, between 81.8 and 131,0 %, and RSD, below 13.8%, are considered acceptable. This method was found to be efficient for the UHPLC-MS/MS determination of avermectins residues in bovine milk with good sensitivity and selectivity.