Determination of Six Sulfonamide Residues in Honey by HPLC with Fluorescence Detection

Six sulfonamides (sulfanilamide, sulfacetamide, sulfadiazine, sulfathiazole, sulfamethazine, sulfamethoxazole) were separated and quantified in honey of different botanic origin using an HPLC-fluorescence detection method. After the acidic hydrolysis, sulfonamides were extracted from honey with a mixture of acetonitrile and dichloromethane, further clean-up on a C18 SPE cartridge and pre-column derivatization with fluorescamine. LC separation was performed on a RP C8 column in gradient mode, in 30 min. The limit of detection was determined at 2µg/kg for sulfadiazine and sulfamethazine, 3µg/kg for sulfanilamide, sulfacetamide and sulfathiazole and 5µg/kg for sulfamethoxazole. The sample clean-up was efficient and recoveries of the analytes in spiked honeys ranged from 47 to 79%.