A fast assay for the simultaneous determination of enrofloxacine and criprofloxacine in milk by high performance liquid chromatography

Abstract

A fast liquid chromatography method with detection of fluorescence for enrofloxacine and ciprofloxacine residues in bovine milk (powder, pasteurized, raw) is reported. The procedures consisted of succesive extraction of milk with acidified ethanol concentrated by dryness and reconstituted for the chromatographic analysis. The analysis is performed by isocratic elution using an acetonitrile-2% acetic acid (15:85) mobile phase and silica dimetiloctadesil column with fluorescence detection at excitation and emission wavelengths of 278 and 450 nm. respectively. The limit of detection and quantification was 5 ng/ml for enrofloxacine and ciprofloxacine. Both analites presented a lineal behaviour when the different concentrations of the pure standars and contaminated matrixes were analyzed; the coefficients of correlation were higher than 0.99. The porcentages of recovery of both analites in the different matrixes were between 82.9 and 115%.