Location: Food and Feed Safety ResearchTitle: Simultaneous screening analysis of 3-methyl-quinoxaline-2-carboxylic acid and quinoxaline-2-carboxylic acid residues in edible animal tissues by a competitive indirect immunoassay Author
Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/3/2013
Publication Date: 10/3/2013
Publication URL: http://handle.nal.usda.gov/10113/58266
Citation: Jiang, W., Beier, R.C., Wang, Z., Wu, Y., Shen, J. 2013. Simultaneous screening analysis of 3-methyl-quinoxaline-2-carboxylic acid and quinoxaline-2-carboxylic acid residues in edible animal tissues by a competitive indirect immunoassay. Journal of Agricultural and Food Chemistry. 61:10018-10025. Interpretive Summary: Enzyme-linked immunosorbent assays (ELISAs) contribute greatly to veterinary drug residue analysis and food safety. An ELISA is an easy-to-use test and is similar to commonly used over-the-counter pregnancy tests. The marker residues for the drugs carbadox and olaquindox are MQCA and QCA, respectively. Carbadox and olaquindox are used in animal production and do not currently have a convenient screening method for the detection of their marker residues. In this study, we developed antibodies that recognize both MQCA and QCA. Antibodies are substances that are produced by the immune system in response to foreign substances which enter the body. Once the antibodies to a foreign substance are isolated, they can be used in a method to detect the presence of that foreign substance. We then used the developed antibody in an ELISA to analyze for MQCA and QCA residues in fish, shrimp, chicken, and pork. The developed method works very well and can be used for screening of MQCA and QCA residues in animal tissues.
Technical Abstract: Immunoassays contribute greatly to veterinary drug residue analysis and food safety, but there are no reported immunoassays on simultaneously detecting MQCA and QCA, the marker residues for carbadox and olaquindox. It is extremely difficult to produce broad-specificity antibodies that bind both residues. In this study, a broad-specificity MAb was successfully produced using a novel hapten. The MAb showed good cross-reactivity with both MQCA and QCA, having IC50 values of 4.8 and 9.6 ng/mL in buffer. The average recoveries ranged from 76 to 108% for spiked samples, and the coefficient of variation ranged from 4.2 to 12.4%. The limit of detection of the ELISA was 1.54 µg/kg. This method was verified by an LC–MS/MS method using naturally contaminated samples, and the correlation coefficient was above 0.98. Here we demonstrate a rapid, simple, and reliable method for the simultaneous screening of MQCA and QCA in edible animal tissues.