Residual detection of buparvaquone, nystatin, and etomidate in animal-derived food products in a single chromatographic run using liquid chromatography-tandem mass spectrometry.

A reliable and highly sensitive screening method based on liquid chromatography coupled withtriple-quadrupoleelectrospray tandemmass spectrometry (LC-MS/MS) analysis has been developed for the detection and quantification of three veterinary drugs, including buparvaquone, nystatin, and etomidate impurity B CRS. The tested drugs were extracted from samples of porcine muscle, pasteurized whole milk, and eggs using 10mM ammonium formate in acetonitrile followed by liquid-liquid purification with n-hexane. Chromatographic separation was achieved on a Phenomenex Luna C18 analytical column using 0.1% formic acid in ultrapure water (A) and acetonitrile (B) as mobile phases. All the matrix-matched calibration curves were linear (R