Development and validation of a highly sensitive quantitative/confirmatory method for the determination of ivermectin residues in bovine tissues by UHPLC-MS/MS

摘要

In this work, a highly sensitive quantitative/confirmatory method was developed for the selective determination of marker residue 22,23-dihydroavermectin B-1a in fat, kidney, liver and muscle bovine tissues using UHPLC-MS/MS. A QuEChERS method and a subsequent d-SPE cleaning with MgSO4 and C18 were used for samples preparation. The method was validated at three levels in each tissue (8.0, 20.0 and 80.0 lg/kg for fat, kidney and muscle, 8.0, 16.0 and 40.0 mu g/kg for liver), taking into account international guidelines. Linearity and matrix effect, accuracy, within-laboratory repeatability, specificity, LOQ, LOD, Q/q relative ion intensities and uncertainty were reported. Recoveries were obtained in the range of 70-120% with within-laboratory repeatability less than 20% for the overall working range. LODs varied from 0.05 to 0.12 mu g/kg. Compound identification was performed using the relative intensities of monitored transitions. The method could be applied to monitoring withdrawal period specified for ivermectin in cattle. (C) 2016 Elsevier Ltd. All rights reserved.