DETERMINATION OF SULFONAMIDES IN EDIBLE SALMON TISSUE BY LIQUID-CHROMATOGRAPHY WITH POSTCOLUMN DERIVATIZATION AND FLUORESCENCE DETECTION

Fourteen sulfonamides-sulfanilamide, sulfadiazine, sulfathiazole, sulf apyridine, sulfamerazine, sulfamethazine, sulfamethizole, sulfamethoxy pyridazine, sulfachloropyridazine, sulfamonomethoxine, sulfadoxine, su lfamethoxazole, sulfadimethoxine, and sulfaquinoxoline-residues of whi ch could be found in aquacultured species, were separated in <25 min b y reversed-phase (C-18) liquid chromatography (LC) with gradient eluti on. Analytes were extracted from edible salmon tissue (muscle and adhe ring skin) with acetonitrile-2% aqueous acetic acid, isolated with 2 l iquid-liquid partitionings, and derivatized with fluorescamine after e luting from the column, The derivatives were detected by fluorescence. Recoveries (n = 4) from coho salmon fortified with sulfonamides at 5, 10, and 20 ng/g tissue averaged 79.7 +/- 7.3, 84.6 +/- 7.7, and 88.2 +/- 7.1%, respectively, Limits of quantitation were 5 ng/g tissue, for sulfanilamide, sulfamethoxypyridazine, and sulfaquinoxoline and 1 ng/ g tissue for the remaining sulfonamides.