Determination of residues of enrofloxacin and its metabolite ciprofloxacinin biological materials by capillary electrophoresis

A method for the analysis of enrofloxacin and ciprofloxacin in chicken musc le using marbofloxacin as internal standard is proposed. Clean-up and pre-c oncentration of the samples are effected by solid-phase extraction and dete rmination is carried out by capillary electrophoresis using a photodiode ar ray detector. The calibration graphs are linear for enrofloxacin and ciprof loxacin from 10 to 300 mug/kg. The method recoveries for enrofloxacin and c iprofloxacin are 74 and 54%, respectively. The limit of detection for the t wo compounds is lower than 25 mug/kg, which allows the detection of positiv e muscle samples at the required maximum residue limits. (C) 2001 Elsevier Science B.V. All rights reserved.