SIMULTANEOUS DETERMINATION OF BENOFLOXACIN, DANOFLOXACIN, ENROFLOXACIN AND OFLOXACIN IN CHICKEN TISSUES BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

A simple, rapid and reliable high-performance liquid chromatographic ( HPLC) method for the simultaneous determination of residual fluoroquin olones (benofloxacin, danofloxacin, enrofloxacin and ofloxacin) in chi cken has been developed. The drugs were extracted with 0.2% metaphosph oric acid-acetonitrile (7:3, v/v), followed by a Bond Elut C18 clean-u p procedure. The HPLC separation was carried out on a Wakosil II 5C18- HG column (150 x 4.6 mm I.D.) with 0.05 M phosphate buffer (pH 2.4)-ac etonitrile (80:20, v/v) containing 2.5 mM 1-heptanesulfonic acid as th e mobile phase. A fluorescence detector was used at an excitation wave length of 295 nm and an emission wavelength of 455 nm. The calibration graphs were linear from 0.1 to 10 ng for danofloxacin and from 1 to 1 00 ng for benofloxacin, enrofloxacin and ofloxacin. The recoveries of the drugs from tissues fortified at a level of 0.2 mug/g were 81.1-89. 6%, and the detection limits were 0.01 mug/g for ofloxacin, danofloxac in and enrofloxacin and 0.02 mug/g for benofloxacin. The time needed p er sample was less than 60 min.