Development and Validation of a Multiresidue Method for the Determination of Macrocyclic Lactones, Monensin, and Fipronil in Bovine Liver by UHPLC-MS/MS Using a QuEChERS Extraction

Macrocyclic lactones (MLs) are widely used as antiparasitic agents in the livestock, monensin (ionophore antibiotics) is recommended in cattle feed as growth-promoting additives, and fipronil is a drug prescripted in animal production to control ectoparasitic infestations. However, the use of these drugs in food-producing animals may lead to the appearance of their residues in meat and offals. A quantitative and confirmatory multiresidue method for determining the presence of macrocyclic lactones (MLs), monensin, and fipronil residues in bovine liver by ultra-high-performance liquid chromatography − tandem mass spectrometry (UHPLC-MS/MS) was developed, optimized, and validated, using a QuEChERS approach. The validation was conducted in accordance with the Decision 657/2002/EC guidelines according to the following parameters: linearity, selectivity, decision limits (CCα), detection capability (CCβ), accuracy, precision, robustness, limits of detection (LOD), limits of quantification (LOQ), and measurement uncertainty. The method presented linearity and selectivity with coefficient of correlation (r) higher than 0.9. LOD ranged from 0.5 to 2.5 µg kg−1, and LOQ was defined from 1.0 to 5.0 µg kg−1 for individual analytes. The accuracy, precision, CCα, CCβ, and uncertainty presented adequate performance. In addition, chicken liver was also satisfactorily validated as an extension of scope. It was concluded that the validated method is suitable to monitor MLs, monensin, and fipronil residues in bovine and chicken livers, and the studied analytes can be detected and quantified at very low concentrations.