Abstract: The determination of sulfonamides veterinary drug residues in eels and roasted eels,including sulfadiazine, sulfamerazine, sulfadimidine, sulfamethoxypyridazine,sulfamethoxaz-ole,sulfamonomethoxine,sulfadimethoxine,sulfaquinoxa- line was studied. Homogenized tissue was extracted with dichloromethane and centrifuged. The supernatant was filtrated and evaporated. The dry residue was dissolved in 1% acetate acid-methanol(65:35, V/V). After addition of hexane, the aqueous layer was collected and diluted with 5% acetate acid. The diluent was applied to a pre-conditioned MCX SPE column, washed with 5% acetate acid-methanol(50:50, V/V) and eluted with 5% ammonia methanol. Elution was analysed by LC on a column (250mm× 4.6mm i.d.) of Cloversil C18 ODS, with 1% acetate acid-methanol as mobile phase(1.0ml/min) and detection at 265nm. The correlation coefficient was larger than 0.999. The detection limit were 0.020mg/kg. The recoveries were in the range of 80%～93%.

Key words: SPE-HPLC, sulfonamides, eels and rosted eels