An HPLC/MS-MS method for the determination of marker residues metabolites of quindoxins in edible tissues of swine and chicken.

A high performance liquid chromatography-tandem mass spectrometry(HPLC/MS-MS) method was developed to simultaneously determine quinoxaline-2-carboxylic acid(QCA) and methyl-3-quinoxaline-2-carboxylic acid(MQCA) that is the marker residues metabolites of quindoxins in edible tissues of swine and chicken.The samples were hydrolyzed with alkaline and extracted by the liquid-liquid method using ethyl acetate,The extraction was dried by nitrogen gas,redissolved in methanol∶0.5% formic acid(30∶70) and filtered ration 0.45 μm micropore film.The final solution was analyzed by HPLC/MS-MS.The decision limits and the detection capabilities of MQCA and QCA in liver and muscle of swine and chicken were 0.2-0.34 μg/kg,0.5-0.9 μg/kg,0.5-0.61 μg/kg and 0.77-1.31 μg/kg,respectively.The relative recovery rate were in the range of 90.07%-106.8%,the inter-day variation were less than 13.69% and the intra-day variation were less than 15.43%.The calibration curves were linear(r20.99) in the range of 2-100 μg/kg.The method was simple and accurate enough to determine the marker residues metabolites of quindoxins in edible tissues of swine and chicken.