Determination of fluoroquinolone residues in animal tissues by liquid chromatography

A simple liquid chromatographic (LC) method was developed for the determina tion of fluoroquinolones (ciprofloxacin, difloxacin, enrofloxacin and saraf loxacin) in animal tissues. Isolation of fluoroquinolones from biological m atrices was performed with 5% trichloroacetic acid-acetonitrile (7:3) solut ion. For clean-up, solid-phase extraction with an SDBI (styrene-divinyloben zene) cartridge was used. LC analyses were performed with analytical column (LiChrospher 100 RP-8 5 mu m) and mobile phase (0.025 M O-phosphoric acid- acetonitrile 70:30, v/v) in ion-pair mode. The whole procedure was validate d in intra- and inter-assay reproducibility and accuracy determination by s imultaneously assaying of muscle, liver and kidney samples supplemented wit h fluoroquinolones at the level of 30 and 60 ng/g, respectively. The statis tical evaluation demonstrates high absolute recovery (>80%) and low coeffic ient of variation (<10%) for all analysed samples. The detection limits for fluoroquinolones were 5 ng/g in muscle, liver and kidney samples. Copyrigh t (C) 1999 John Wiley & Sons, Ltd.