Submitted to: Journal of Chromatography B
Publication Type: Peer reviewed journal
Publication Acceptance Date: 8/4/2006
Publication Date: 8/23/2006
Citation: Schneider, M.J., Bradenbuber, S.E., Reyes-Herrera, I., Donoghue, D.J. 2006. Simultaneous determination of fluoroquinolones and tetracyclines in chicken muscle using hplc with fluorescence detection. Journal of Chromatography B.846:8-13. Interpretive Summary: Use of veterinary drugs in food animals can potentially lead to the presence of drug residues in the food supply. Efficient methods are required to monitor the food supply to ensure drug residues are not present at a level which would be harmful to consumers. Many methods which have been developed are designed to determine amounts of a single drug. Increasingly, methods which permit analysis of multiple members of one drug class are being developed, leading to greater efficiency of analysis. We have now developed a method which allows analysis of multiple members of two different classes of veterinary drugs in chicken muscle, the fluoroquinolone and tetracycline antibiotics. This method relies on a simple extraction of the drugs from the chicken muscle, separation of these drugs by liquid chromatography, and detection of the drugs by fluorescence. With this method, we have successfully and simultaneously recovered and measured levels of 5 fluoroquinolones and 3 tetracyclines from chicken muscle. The method was also successful in analysis of enrofloxacin and oxytetracycline in chickens which had been dosed with one of these drugs. The efficiency of this method should facilitate its use by regulatory agencies in monitoring fluoroquinolone and tetracycline antibiotics in chicken muscle.
Technical Abstract: A multiresidue method has been developed which allows for the simultaneous determination of both fluoroquinolones and tetracyclines in chicken muscle. Samples were extracted with a mix of acetonitrile and 0.1 M citrate, 150 mM Mg+2, pH 5.0. After centrifugation and evaporation, the extracts could be analyzed by liquid chromatography with fluorescence detection. Good recoveries (63-95%) were obtained from samples fortified with a mix of five fluoroquinolones and 3 tetracyclines, with satisfactory relative standard deviations. Limits of detection were 0.5 ng/g (danofloxacin), 1 ng/g (oxytetracycline, ciprofloxacin, enrofloxacin), 1.5 ng/g (tetracycline), 2 ng/g (difloxacin) and 5 ng/g (sarafloxacin and chlortetracycline). Enrofloxacin and its metabolite ciprofloxacin, as well as oxytetracycline were determined in enrofloxacin and oxytetracycline incurred chicken muscle using this method.