title: Determination of marker residue of Olaquindox in fish tissue by ultra performance liquid chromatography-tandem mass spectrometry.
abstract: Methyl-3-quinoxaline-2-carboxylic acid (MQCA) is the last major remaining detectable metabolite of Olaquindox in animal tissue. A rapid, sensitive and specific ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed for the detection and quantification of MQCA in fish tissue using deuterated quinoxaline-2-carboxylic acid (d(4)-QCA) as internal standard. Various parameters affecting sample preparation, LC separation and MS/MS detection were investigated, and the optimal conditions concerned were determined. Fish tissue samples were subject to hydrochloric acid hydrolysis followed by Oasis MAX solid-phase extraction clean-up; analysis was performed using UPLC coupled to electrospray MS/MS. The chromatographic separation was achieved in less than 5 min. The limit of detection and the limit of quantification were 0.1 and 0.25 ng/g, respectively. The average recoveries of MQCA, spiked at levels of 0.25-50.0 ng/g, were from 92.7 to 104.3%. The relative standard deviation values were <6%. The validated method was successfully applied to analyze 60 batch samples collected from the local market.
authors.affiliation: School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, PR China.
authors.forename: Xiaojun
authors.initials: X
authors.lastname: Zhang
authors.forename: Bin
authors.initials: B
authors.lastname: Zheng
authors.forename: Hong
authors.initials: H
authors.lastname: Zhang
authors.forename: Xuechang
authors.initials: X
authors.lastname: Chen
authors.forename: Guangming
authors.initials: G
authors.lastname: Mei
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000032:analysis* / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004350:Drug Residues / Q000032:analysis* / Q000378:metabolism; D005399:Fishes / Q000378:metabolism; D005506:Food Contamination / Q000032:analysis; D009132:Muscles / Q000737:chemistry; D011810:Quinoxalines / Q000032:analysis* / Q000378:metabolism; D017747:Seafood / Q000032:analysis*; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D000900:Anti-Bacterial Agents; D011810:Quinoxalines; C013168:olaquindox