HPLC RESIDUES OF ENROFLOXACIN AND CIPROFLOXACIN IN EGGS OF LAYING HENS

Eggs of 12 laying hens with 5 mg/kg/day oral administration of 5% enro floxacin (EFX) or ciprofloxacin (CFX) solution during 5 days contained residues from 0.02 to 1.98 mu g/g (EFX) or 0.14 to 0.28 mu g/g (CFX). At identical dosage regime High Performance Liquid Chromatograhy (HPL C) residues of EFX were 6-fold greater than CFX ones. Maximun concentr ations were detected at the second day after the administration withdr awal. The limits of detection were 0.019 mu g/g for EFX and 0.156 mu g /g for CFX. The recovery was 36-50% for CFX and 49-85% for EFX. The wi thdrawal treatment periods in hens are six days for EFX and five days for CFX in order to avoid violative levels of egg residues. (C) 1997 E lsevier Science B.V.