Quantitative determination of sulfonamide residues in foods of animal origin by high-performance liquid chromatography with fluorescence detection

An HPLC method with fluorescence detection is proposed for the quantitative determination of residues of ten of the most used sulfonamides as their derivatives. Sulfonamides were isolated from meat, mix meat and kidney with ethyl acetate (first extraction) and acetone (second extraction) and further purified by partitioning three times with water–methylene chloride. The recovery for mix meat spiked with 1, 5 and 10 μg/kg of sulfonamides averaged 64%, 68% and 75%, respectively. Limits of quantitation were 1 μg/kg for sulfaquinoxaline and 0.5 μg/kg for the remaining sulfonamides.