Quantitative determination of sulfonamides in hen eggs by high performance liquid chromatography method

Abstract

The recent study was conducted to determine the sulfonamide residues in hen eggs. Sulfonamides (SAs), synthetic antibiotics, are frequently used in Vietnam in poultry production as therapeutic or prophylactic modes or as growth promoters. Three common SAs, sulfadiazine (SDZ), sulfamethazine (SMZ) and sulfamethoxazole (SMX), were detected in hen eggsamplesby utilizing HPLC method with UV detector set at a wavelength of 268 nm using C18 column (250 x 4.6 nm x 5μm)under isocratic conditions and using potassium dihydrogen phosphate (KH2PO4) buffer and acetonitrile (80:20, v/v) as a mobile phase with a flow rate of 1 ml/min. A total of 60 samples, each consisting of 12 eggs, were collected casually from markets and supermarkets in district 10, 11 and Tan Binh district. These egg samples were stored at 4oC until the time of analysis. It was noted that 20% of samples had detectable levels of sulfonamides residues while 6.67% of samples exceeded the maximum residue level (MRL) and were unacceptable for human usage. Among the 60 samples, sulfadiazine was determined in 8.33% of samples and 2 of them (3.33%)had the sulfadiazine concentration were greater than the MRL. There were 3.3% of samples which had sulfamethazine whereas only 1 sample infringed upon the MRL. Sulfamethoxazole was detected in 8.3% of samples and among of them 1 (1.67%) sample exceeded the MRL. Moreover, samples which were collected from supermarkets showed a significantly different results compared with samples that were bought from markets. Only 1 sample from supermarkets surpassed the MRL even though 3 samples that were collected from markets exceeded the MRL. New strategies should be established to monitor the usage of the SAs. Key words: antibiotics, sulfonamide residues, sulfadiazine (SDZ), sulfamethazine (SMZ), sulfamethoxazole (SMX), hen eggs, HPLC.