Screening of quinolone residues in pig muscle by planar chromatography

A high-performance thin-layer chromatographic method based on solid-phase extraction has been developed for the qualitative determination of seven quinolones (enrofloxacin, ciprofloxacin, danofloxacin, norfloxacin, flumequine, oxolinic acid and nalidixic acid) in pork muscle. After preparation of the samples by extraction and clean-up by solid-phase extraction on reversed-phase cartridges, extracts were spotted and eluted on silica gel plates. The plate is first inspected under UV illumination at 312 nm, then sprayed with terbium chloride solution and again monitored under 312 nm UV. The method has been validated to a level of 15 mu g kg(-1) for enrofloxacin, ciprofloxacin, danofloxacin, norfloxacin and 5 mu g kg(-1) for flumequin, oxolinic acid and nalidixic acid.