Simultaneous Determination of the Residues of Ciprofloxacin, Danofloxacin and Enrofloxacin in Eggs by HPLC

HPLC was applied to the simultaneous determination of the residues of ciprofloxacin, danofloxacin and enrofloxacin in eggs. The sample was treated with acidic methanol for extraction by ultrasonic. The extract solution was degeased with acetonitrile. The supernatant was separated on a Purospher STAR LP RP-18 chromatographic column, with a mixture of acetonitrile and 0.05 mol·L-1 phosphoric acid solution (pH 2.4) for elution. Fluorescence detector was used with λex of 280 nm and λem of 450 nm. The linearity ranges of ciprofloxacin, danofloxacin and enrofloxacin were 0.005-0.50, 0.001-0.10, 0.005-0.50 mg·L-1, respectively, with detection limits of 0.8, 0.1, 0.6 μg· kg-1, respectively. Recovery rates obtained by standard addition method were in the range of 91.5%-98.3%, and RSDs (n=6) were in the range of 0.45%-1.3%.