Detection of macrocyclic lactones in porcine liver, meat and fish tissue using LC-APCI-MS-MS

A selective and sensitive method for the simultaneous determination of five avermectins (abamectin, ivermectin, doramectin, emamectin and eprinomectin) and one milbemycin (moxidectin) in porcine liver, bovine meat and fish tissue was developed. The method involved extraction with acetonitrile and purification by C18 solid-phase extraction. Detection was carried out using liquid chromatography coupled to multiple mass spectrometry (LC-MS2) equipped with APCI in the negative mode. This method was validated according to the requirements of Commission Decision EC/2002/657 (Implementing Council Directive 96/23/EC concerning the performance of analytical methods and the interpretation of results. Off J Eur Commun. L221: 8-36.). In addition to the linear response (R2 between 59 and 97%), good repeatability (CV between 20 and 35%), reproducibility (CV between 20 and 35%) and detection (CC) and quantification (CC) limits were obtained for all compounds in all matrices considered