Simultaneous Determination of Cyadox and Its Metabolites in Chicken Tissues by LC-MS/MS

A specific and sensitive LC-MS/MS method was firstly established for the simultaneous extraction and determination of cyadox and its three main metabolites—1,4-bisdesoxycyadox, 4-desoxycyadox, and quinoxaline-2-carboxylic acid—in chicken muscle, liver, kidney, and fat tissues. Samples were subjected to extraction using ethyl acetate and followed by acetonitrile–chloroform (1:4, v/v) and further purified by Oasis mixed mode anion exchange SPE cartridge. Analysis was performed on a C18 column by detection with MS in multiple-reaction monitoring mode. A gradient elution program with 0.1 % formic acid solution, acetonitrile, and 1 % formic acid (adjusted to pH 8 with ammonia) was performed at a flow rate of 0.2 mL min−1. The correlation coefficients (r) for each calibration curve are higher than 0.99 within the experimental concentration range. The recoveries of the four target analytes at three spiking levels of 2.5, 25 and 250 μg kg−1 were between 74.5 and 93.8 %, with relative standard deviations less than 12 %. The decision limits (CCαs) of the four analytes in chicken edible tissues ranged from 0.3 to 1.5 μg kg−1, and the detection capabilities (CCβs) were below 2.3 μg kg−1. The developed method demonstrated a satisfactory applicability in incurred chicken tissue samples.