High-performance liquid chromatographic determination of sulfadimidine residues in eggs

Abstract

Sulfadimidine is widely used for the treatment of coccidiosis in laying hens at the dose of 2 gl-1 for 6 consecutive days via the drinking water. As a result, there is concern that the residues of this drug may be retained in the eggs and present a potential risk to human health. The aim of our study was to determine the residue concentrations of sulfadimidine in whole eggs of laying hens during and after its oral administration up to the 15 th day of the withdrawal period. The sulfadimidine residues were determined by a gradient high-performance liquid chromatography system with a photo-diode array detector at 275 nm. Our results indicate that the oral administration of sulfadimidine to laying hens produced a rapid and sustained increase in sulfadimidine residues in their eggs. The highest residue concentrations of sulfadimidine were found on the 6th day of administration. After withdrawal, the residues declined rapidly, but they were still detectable on the 10th day of the withdrawal period. On day 11, the residues were below the established MRL (0.1 mg·kg-1). The limit of quantification (LOQ) for sulfadimidine was 0.3 mg·kg -1, the detection limit (LOD) was 0.09 mg·kg-1, and the recovery ranged from 91 to 98%.