Abstract: In 0.1 mol·L -1 NH 3 NH 4Cl buffer solution(pH 9.2),a sensitive reduction peak of complex of ciprofloxacin (CPFX) with manganese (Mn) was obtained by single sweep oscillopolarograph. The peak potential( Ep ) is -1.61 V(vs.SCE). The peak current ( i p) is proportional to the concentration of Mn(Ⅱ) over the range of 5×10 -6 ～2×10 -5 mol·L -1 . It is possible to be applied to the determination of Mn(Ⅱ). The polarographyic and voltammetric behaviour of complex was studied in detail. The ratio of CPFX∶Mn in the complex was 2∶1. The electrode reaction mechanism was discussed.

Key words: Ciprofloxacin, Mn(Ⅱ), Complex, Polarography, Voltammetry, Reduction mechanism