1.Determination of quinocetone and its two major metabolites in chicken liver and muscle tissues by liquid chromatography-tandem mass spectrometry
Junjian Fang, Yong Li, Fangting Dong*. Anal. Methods, 2012, 4, 1149
Quinocetone (3-methyl-2-cinnamicacyl-l,4-dioxyquioxaline) is a new member of the quinoxaline-1,4-dioxide family like carbadox and olaquindox, which have been widely used in China as antimicrobial agents to improve feeding efﬁciency in food-producing animals. But since 2003, the use of carbadox and olaquindox as a feed additive is no longer authorized in China due to their toxicity. As a replacement of those two veterinary drugs, quinocetone is thought of as having more effectiveness, less toxicity and more safety and is approved for use in the feedstuff of poultry and other livestock by the Ministry of Agriculture of China in 2003. Quinocetone was ﬁrstly developed by Lanzhou Institute of Animal Husbandry and Veterinary Drugs, Chinese Academy of Agricultural Sciences (Lanzhou, China) in the 1990s. In recent years, the researchers of quinocetone were focused on toxicological evaluation, metabolites identiﬁcation and pharmacokinetic and residue study. To protect human health, it is necessary to monitor quinocetone residues in edible animal tissues. In order to measure the disposition (i.e., distribution) of QTN and its metabolites in animal tissues, a validated, highly sensitive analytical method is required.
2.Determination of quinoxaline antibiotics in ﬁsh feed by enzyme-linked immunosorbent assay using a monoclonal antibody
Juan Peng, Dezhao Kong, Liqiang Liu, Shanshan Song, Hua Kuang and C huanlai Xu*. Anal. Methods,2015, 7, 5204–5209
Immunoassays have been developed for OLA residue detection. However, few researchers have used monoclonal antibody based-ELISA for QCT and MEQ detection. The simultaneous detection of multi-residue quinoxaline antibiotics has been reported. In 2013, Le et al. developed an ELISA for the simultaneous measurement of five quinoxaline-1,4-dioxides (OLA, QCT, CBX, MEQ, and CYA) in porcine and chicken feeds using QCT modified with para-amino benzoic acid. The results revealed that the half maximal inhibitory concentration (IC50) values were 26.4, 8.6, 17.3, 24.5, and 13.1 ng ml-1 for OLA, QCT, CBX, MEQ, and CYA, respectively. Cheng et al. developed an ELISA to simultaneously measure OLA, QCT, CBX, MEQ, and QCA levels in swine liver using olaquindox succinic anhydride derivatives as antigens; the IC50 values were 1.34, 2.5, 0.38, 0.36, and 1.11 ng ml-1, respectively. However, these methods were developed based on polyclonal antibodies. Few studies have focused on immunoassays based on highly specific and sensitive monoclonal antibodies against OLA, QCT, and MEQ.