Simultaneous determination of fluoroquinolones and tetracyclines in chicken muscle using HPLC with fluorescence detection.

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 MgCl(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 three 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, chlortetracycline). Enrofloxacin and its metabolite ciprofloxacin, as well as oxytetracycline were determined in enrofloxacin and oxytetracycline incurred chicken muscle using this method.