Chromatographic Residue Analysis of Sulfonamides in Foodstuffs of Animal Origin

Abstract

The widespread use of antibiotics in veterinary medicine for prophylactic, therapeutic and growth promoting purposes may result in the presence of residues in foodstuff of animal origin. Sulfonamides, N‐derivatives of 4‐amino‐benzenesulfonamide, belong to a diverse class of synthetic antibiotics consisting of chemically related compounds. A number of them e.g., sulfamethazine, sulfadiazine, sulfaquinoxaline and sulfamethoxypyridazine, are widely used in animal husbandry. Their residues in food are of great concern because of their potential carcinogenic character and because they may contribute to the development of antibiotic resistance in humans. These facts have induced most of the regulatory activities on sulfonamides. Regulatory bodies in the European Union as well as in other countries have set different maximum residue limits in various tissues. These regulations have stimulated the development of fast, accurate and sensitive analytical methods for monitoring sulfonamide residues in food samples of animal origin. Gas chromatography methods tend to be time‐consuming due to the required previous cleanup and derivatization procedures, thus, HPLC methods with UV or MS detection have the leading position. These and other aspects of current analytical methodology, including sample preparation and cleanup, are reviewed and discussed. Emphasis is given to confirmatory methods since these comprise useful tools to regulatory agencies, and identifications based on these methods can be used in support of regulatory action.