Abstract: A new method for the determination of 14 sulfonamide (sulfanilamide, sulfadiazine, sulfathiazole, sulfamerazine, sulfameter, sulfamethazine, sulfamethoxypyridazine, sulfachlorpyridazine, sulfamonomethoxine, sulfamethoxazole, sulfadoxine, sulfafurazole, sulfadimethoxine, and sulfaquinoxaline) residues in fishery products using high performance liquid chromatography (HPLC) equipped with fluorescence detector was established. Homogenized samples were extracted with ethylacetate, reverse-extracted into hydrochloric acid, defatted with hexane, separated by reversed-phase column chromatography, treated by on-line post-column derivatization, detected using a fluorescence detector, and quantified using the internal standard method. The linear range of the method for detecting the sulfonamides was from 2.5 to 800 μg/L, and the relative coefficients were all above 0.9934. The mean recoveries across spike levels varying from 2.5 to 200μg/kg were between 88.9% and 98.6% with RSDs less than 6.96%. The limits of quantification for the sulfonamides were 2.5－20μg/kg. The method exhibited good repeatability, high sensitivity, little interference and was widely suitable for the determination of sulfonamide residues in aquatic products.

Key words: fishery products, high performance liquid chromatography, online post-column derivatization, sulfonamides