Electrochemical studies of some quinolone antibiotics. Part I. Qualitative analysis on mercury and carbon electrodes.

Direct current polarography and cyclic voltammetry was used to study quinolone antibiotics: ciprofloxacin, enoxacin, norfloxacin, ofloxacin and pefloxacin on a mercury and carbon electrode. The dependence of limiting currents and half-wave potentials on the pH of the solution, mercury head, temperature, ionic strength of the solution, methyl cellulose concentration, scan rate and quinolone concentration was studied. The optimal parameters and background solutions have been chosen. It was concluded that on mercury electrode quinolones are reduced in two one-electron waves and the process of the reduction is accompanied by an acid-base equilibrium. An anodic peak observed on graphite electrode is probably caused by the oxidation of piperazine ring in the molecule.