Multiresidue method for simultaneous determination of quinolone antibacterials in pig kidney samples by liquid chromatography with fluorescence detection

A new analytical method for simultaneous determination of eight quinolones namely, ciprofloxacin, danofloxacin, difloxacin, enrofloxacin, flumequine, marbofloxacin, oxolinic acid and sarafloxacin, in pig kidney samples was developed. The procedure involves the extraction of the quinolones from the samples by traditional extraction, a step for clean-up and preconcentration of the analytes by solid-phase extraction (SPE) and subsequent liquid chromatography separation with fluorescence detection (LC–FD). The mobile phase was composed of acetonitrile and 10 mM citrate buffer solution of pH 4.5, with an initial composition of acetonitrile–water 12:88 (v/v) and using linear gradient elution. Norfloxacin was used as internal standard. The limits of detection (1–8 μg kg−1) and the limits of quantification (5–27 μg kg−1) found were lower than the maximum residue limits regulated by the European Union for these compounds in pig kidney.