title: Simultaneous determination of mequindox, quinocetone, and their major metabolites in chicken and pork by UPLC-MS/MS.
abstract: This report presents a UPLC-MS/MS method for determination of mequindox (MEQ), quinocetone (QCT) and their 11 metabolites in chicken and pork samples. Following extraction process with acetonitrile-ethyl acetate, acidulation, and re-extraction with ethyl acetate in turn, target analytes were further purified using C18 solid phase extraction (SPE) cartridges for UPLC-MS/MS analysis. Validation was processed with mean recoveries from 69.1% to 113.3% with intra-day relative standard deviation (RSD) <14.7%, inter-day RSD <19.2%, and limit of detection between 0.05 and 1.0 μg/kg for each analytes. The verified method was successfully applied to the quantitative determination of commercial samples. This developed procedure will help to control food animal products with MEQ and QCT residues, and facilitate further pharmacokinetic and residue studies of similar quinoxaline-1,4-dioxide veterinary drugs.
authors.affiliation: College of Life Science, Yantai University, Yantai 264005, PR China. Electronic address: yizhanwangpai@163.com.
authors.forename: Yanshen
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Veterinary Pharmacology and Toxicology, College of Veterinary Medicine, China Agricultural University, Beijing 100193, PR China; Beijing Fengtai District Animal Health Inspection, Beijing, PR China.
authors.forename: Kaili
authors.initials: K
authors.lastname: Liu
authors.affiliation: Food and Feed Safety Research Unit, Southern Plains Agricultural Research Center, Agricultural Research Service, U.S. Department of Agriculture, 2881 F&B Road, College Station, TX 77845-4988, USA.
authors.forename: Ross C
authors.initials: RC
authors.lastname: Beier
authors.affiliation: Department of Veterinary Pharmacology and Toxicology, College of Veterinary Medicine, China Agricultural University, Beijing 100193, PR China.
authors.forename: Xingyuan
authors.initials: X
authors.lastname: Cao
authors.affiliation: Department of Veterinary Pharmacology and Toxicology, College of Veterinary Medicine, China Agricultural University, Beijing 100193, PR China.
authors.forename: Jianzhong
authors.initials: J
authors.lastname: Shen
authors.affiliation: Department of Veterinary Pharmacology and Toxicology, College of Veterinary Medicine, China Agricultural University, Beijing 100193, PR China. Electronic address: suxia@cau.edu.cn.
authors.forename: Suxia
authors.initials: S
authors.lastname: Zhang
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000032:analysis*; D002645:Chickens; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D005506:Food Contamination / Q000032:analysis; D008460:Meat / Q000032:analysis*; D011810:Quinoxalines / Q000032:analysis*; D052616:Solid Phase Extraction / Q000379:methods; D013552:Swine; D053719:Tandem Mass Spectrometry / Q000379:methods; D019155:Veterinary Drugs / Q000032:analysis
chemical_list: D000900:Anti-Bacterial Agents; C545385:Mequindox; D011810:Quinoxalines; D019155:Veterinary Drugs; C502851:quinocetone
keywords: Mequindox; Metabolites; Quinocetone; Residue analysis; UPLC–MS/MS