Analysis of Veterinary Drug and Pesticide Residues Using the Ethyl Acetate Multiclass/Multiresidue Method in Milk by Liquid Chromatography-Tandem Mass Spectrometry

A rapid and simple multiclass,ethyl acetate (etoac) multiresidue method based on liquid chromatography coupled with tandem mass spectrometry (lc-ms/ms) detection was developed for the determination and quantification of 26 veterinary drugs and 187 total pesticide residues in milk. sample preparation was a simple procedure based on liquid-liquid extraction with ethyl acetate containing 0.1% acetic acid,followed by centrifugation and evaporation of the supernatant. the residue was dissolved in ethyl acetate with 0.1% acetic acid and centrifuged prior to lc-ms/ms analysis. chromatographic separation of analytes was performed on an inertsil x-terra c18 column with acetic acid in methanol and water gradient. the repeatability and reproducibility were in the range of 2 to 13% and 6 to 16%,respectively. the average recoveries ranged from 75 to 120% with the rsd (n = 18). the developed method was validated according to the criteria set in commission decision 2002/657/ec and sante/11945/2015. the validated methodology represents a fast and cheap alternative for the simultaneous analysis of veterinary drug and pesticide residues which can be easily extended to other compounds and matrices. © 2016 husniye imamoglu and elmas oktem olgun.