title: Development of liquid chromatographic methods for determination of quinocetone and its main metabolites in edible tissues of swine and chicken.
abstract: Quinocetone (QCT), a new antimicrobial growth promotant of quinoxalines, can effectively improve the growth and feed efficiency of food animals with more safety than is provided by olaquindox and carbadox. To clarify its metabolism and residue levels in animals, a liquid chromatographic method with UV-Vis detection was developed for the determination of QCT and its main metabolites, desoxyquinocetone (DQCT) and 3-methylquinoxaline-2-carboxylic acid (MQCA), in muscle, liver, kidney, and fat of swine and chicken. For sample pretreatment, QCT and DQCT were extracted with ethyl acetate and purified with iso-octane; after alkaline hydrolysis of the tissue, MQCA was extracted with ethyl acetate and citric acid buffer (pH 6.0), and the extract was purified over a cation-exchange column (AG MP-50 resin). Detection was at 312 and 320 nm for QCT and DQCT, respectively, and at 320 nm for MQCA. The observed limit of detection for the 3 compounds was 0.025 microg/g in various tissues. The methods were linear over the concentrations range of 0.01-0.64 microg/mL with mean recoveries of approximately 71-86% and relative standard deviations of about 4-12% at the levels of 0.05, 0.10, and 0.20 microg/g. The method is highly selective and can be applied to the determination of QCT and its main metabolites in animal tissues, which would accelerate the pharmacokinetic and residue study of QCT in food animals.
authors.affiliation: Reference Laboratory State of Veterinary Drug Residues, MOA Key Laboratory of Food Safety Evaluation, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei 430070, People's Republic of China.
authors.forename: Lingli
authors.initials: L
authors.lastname: Huang
authors.forename: Aiguo
authors.initials: A
authors.lastname: Xiao
authors.forename: Shengxian
authors.initials: S
authors.lastname: Fan
authors.forename: Juyi
authors.initials: J
authors.lastname: Yin
authors.forename: Pin
authors.initials: P
authors.lastname: Chen
authors.forename: Dengcai
authors.initials: D
authors.lastname: Liu
authors.forename: Yinsheng
authors.initials: Y
authors.lastname: Qiu
authors.forename: Yulian
authors.initials: Y
authors.lastname: Wang
authors.forename: Zonghui
authors.initials: Z
authors.lastname: Yuan
mesh_terms: D000818:Animals; D000890:Anti-Infective Agents / Q000032:analysis* / Q000493:pharmacokinetics; D001711:Biotransformation; D002138:Calibration; D002645:Chickens; D002853:Chromatography, Liquid; D004350:Drug Residues / Q000032:analysis*; D006868:Hydrolysis; D007202:Indicators and Reagents; D008460:Meat / Q000032:analysis*; D011810:Quinoxalines / Q000032:analysis* / Q000493:pharmacokinetics; D012015:Reference Standards; D012995:Solubility; D012996:Solutions; D013056:Spectrophotometry, Ultraviolet; D013552:Swine
chemical_list: D000890:Anti-Infective Agents; D007202:Indicators and Reagents; D011810:Quinoxalines; D012996:Solutions; C502851:quinocetone