Quantitative Determination of Quinocetone and Its Metabolites in Chicken Plasma by Liquid Chromatography/Tandem Mass Spectrometry

A new method has been established for the simultaneous determination of the new veterinary drug quinocetone (3-methyl-2-cinnamoyl-N-1,4-dioxyquioxaline; QTN) and its 2 metabolites de-monoxy-quinocetone (3-methyl-2-cinnamoyl-N-1-monoxyquinoxaline; DMO-QTN) and de-dioxy-quinocetone (3-methyl-2-cinnamoyl-N-quinoxaline; DDI-QTN) in chicken plasma by liquid chromatography/tandem mass spectrometry (LC/MS/MS). The detection was performed using electrospray ionization in multiple reaction monitoring mode. The analysis of the linearity, accuracy, and precision of the method is described. The limits of detection and quantification of the LC/MS/MS method used for testing QTN, DMO-QTN, and DDI-QTN were 0.002 and 0.008 mu g/mL; 0.002 and 0.008 mu g/mL; and 0.003 and 0.010 mu g/mL, respectively. The method was validated and can be used in future pharmacokinetic studies.