Abstract:

A method of high performance liquid chromatography with post-column derivatization and terbium sensitized fluorescence for simultaneous determination of residues of ciprofloxacin, norfloxacin and enrofloxacin in chicken was established, based on the effect that Tb3+ can sensibilize fluorescence of fluoroquinolones. Under the optimal chromatographic condition, three fluoroquinolones were separated on a C18 column with 0.05 mol/L acetic acid/acetate buffer-acetonitrile (89∶11, v/v) as the mobile phase, and at a flow rate of 0.8 mL/min; then were derivatized with 8×10-5 mol/L Tb3+ at 40 ℃, and at a flow rate of 0.5 mL/min; finally were detected using a fluorescence detector (λex=271 nm, λem=545 nm). The recoveries of three fluoroquinolones ranged from 66.3%-88.0% at the added levels of 1.0, 10.0, 50.0, and 100.0 ng/g, and the relative standard deviations (RSDs) were less than 15.0%. The linear range for quantitative analysis was between 0.1 and 500 ng/mL. All the RSDs of the inter-day and intra-day analyses were less than 13.0%. The detection limits were 0.05 ng/g for ciprofloxacin and norfloxacin and 0.08 ng/g for enrofloxacin. The method is sensitive for the determination of multi-residues of fluoroquinolones in chicken.

Key words: chicken , fluoroquinolone drugs, mutil-residues, post-column derivatization, terbium, high performance liquid chromatography (HPLC)