Depletion of florfenicol and florfenicol amine residues in chicken eggs

The aim of this study was to develop a suitable method for the analysis of florfenicol (FF) and its metabolite florfenicol amine (FFA) in chicken eggs and to determine FF and FFA residue depletion in eggs of laying hens.2. The analytes were extracted from yolk, albumen and whole egg by phosphate buffer and ethyl acetate.

Following purification, samples were analysed by high-performance liquid chromatography.3. Fifty laying hens were divided into 5 groups, and each hen received doses of 20 mg/kg FF: Group 1 (received a single oral dose by gavage); Group 2 (a single intramuscular dose); Group 3 (a single subcutaneous dose); Group 4 (multiple oral doses for 3 d) and Group 5 (multiple oral doses for 5 d).4. Limits of detection and of quantitation values were 1.94 and 6.45 g/10 9 g (ppb) for FF, respectively, and 0.48 and 1.58 ppb for FFA, respectively.