Abstract:

A solid-phase extraction followed by reversed-phase high performance liquid chromatographic (SPE-RP-HPLC) method was presented for the simultaneous determination of 6 quinolone residues (enrofloxacin, ciprofloxacin, norfloxacin, ofloxacin, oxolinic acid and flumequine) in aquatic products. Sample extraction, cleanup on a C18 cartilage column and chromatographic separation were investigated. A RP-HPLC system equipped with fluorescence detector (λex = 280 nm, λem = 480 nm) was used for analyzing 6 quinolones, and their quantification was achieved by external standard method. Six quinolones exhibited good linearity within the range of 0.02－2.0 μg/mL and the regression coefficients were all over 0.99. The developed method showed limits of detection of 2 μg/kg for ciprofloxacin, enrofloxacin, norfloxacin, ofloxacin and 5 μg/kg for oxolinic acid and flumequine (RSN = 3), and limits of quantification of 5 μg/kg for ciprofloxacin, enrofloxacin, norfloxacin, ofloxacin and 10μg/kg for oxolinic acid and flumequine (RSN = 10). Satisfying results were obtained in spike recovery experiments and average spike recoveries of 5 replicates at three levels were within the range of 78.8%－92.9%, with RSD range of 2.97%－7.10%. This method, thanks to its simplicity, sensitivity and reliability, has good suitability for the simultaneous determination of 6 quinolone residues in aquatic products.

Key words: reversed-phase high performance liquid chromatography (RP-HPLC), fluorescence spectroscopy, quinolones , multi-residue determination, aquatic products