RP-HPLC method for detection and quantification of residual fluoroquinolones in buffalo meat

Abstract

A reverse-phase liquid chromatographic method for simultaneous quantification of enrofloxacin and its active metabolite ciprofloxacin in buffalo meat matrix is described. The method entails simple liquid-liquid extraction of meat samples. After extraction of the meat samples for the two fluoroquinolones, the analysis of the drugs was carried out using a reverse phase C18 column at an oven temperature of 40ºC. The chromatographic separation was accomplished with mobile phase consisting of 0.1% aqueous formic acid and 0.1% formic acid in acetonitrile (80:20, v/v) in an isocratic elution mode. The flow rate of the mobile phase was maintained at 1.2 ml/min and injection volume was 20 μl. A fluorescent detector was operated at an excitation and emission wavelength of 280 and 450 nm. The assay was linear in the concentrations ranging from 10 to 200 μg/kg. Mean extraction recoveries of enrofloxacin and ciprofloxacin were in the range of 70–88%. The limits of quantification for enrofloxacin and ciprofloxacin were 36 and 30 μg/kg, respectively. This RP-HPLC method has highly applicability for routine analysis of residual fluoroquinolones in buffalo meat below Codex MRL.