Research on the Residual Detection of Quinocetone,Cyadox and Their Main Metabolites in Aquatic Products by HPLC-MS/MS

KeyWord:aquatic products  quinocetone(QCT)  cyadox(CYA)  metabolites  high performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS)

Abstract:

      A high performance liquid chromatography-tandem mass spectrometric(HPLC-MS/MS) method was established for the determination of the residual quinocetone(QCT), cyadox(CYA), bidesoxyquinocetone(BDQCT), methyl-3-quinoxaline-2-carboxylic acid(MQCA), bidesoxycyadox(BDCYA) and quinoxaline-2-carboxylic acid(QCA) in aquatic products. Samples were extracted with acetonitrile-ethyl acetate(1¡Ã1) and hydrochloric acid solution, then cleaned up on a MAX solid-phase extraction cartridge. The separation of QCA,BDQCT,MQCA,CYA,BDCYA and QCT was carried out on a Waters XBridge C18 column using methanol, acetonitrile and 0.1% fomic acid as mobile phase. The identification of six analytes was performed by selective reaction monitoring in positive electrospray ionization, and the quantification was done by the external standard method. The calibration curves of six analytes were linear in the range of 2-500¦Ìg/L. At the fortified levels of 5-50¦Ìg/kg,the recoveries ranged from 76.3% to 94.2%,with RSDs of 4.2% to 11.7%.The limits of detection(LOD) were in the range of 0.5-1.6¦Ìg/kg and the limit of quantitation(LOQ) were 2.0-5.0¦Ìg/kg. The results showed that the method could be used to analyze simultaneously QCT, CYA and their metabolites residues in aquatic products.