Abstract: The polarographic and voltammetric behavior of ciprofloxacin lactate (CFL) and its application were studied.In 0.02 mol/L NH₄Cl-NH₃. H₂O buffer solution (pH= 8.3),a well-defined reduction peak was yielded by CFL.The peak potential(Ep) is about -1.61 V (vs-SCE).Alinear relationship holds between the differential peak height and the concen tration of CFLin the range of 3.9×10^-8～1.8×10^-5 mol/Land 1.8 ×10^-6～1.1×10^-5 mol/L, respectively, with r= 0.9997.The limiting detection is 2.5×10^-8 mol/L.Most of metallic ions do not interfere the determination.This method is used to determine CFLin raw samples and injections with RSD 0.38%～0.72% and recoveries 99.2%～101.4%, and can also be used to determine the trace CFLin serum, plasma and urine samples.It may provide a simple, rapid and sensitive method for determining clinical medicine and pharmacokinetics.The experimental results show that the reduction of CFLbelongs to an irreversible process of reactant adsorption.The electrode reaction mechanism was preliminarily presented.

Key words: Ciprofloxacin lactate, Single-sweep oscillopolarography, Polarographic behavior, Adsorptive wave