VOLTAMMETRIC STUDY OF CEFSULODIN - SURFACE REDUCTION OF THE ISONICOTINAMIDE SUBSTITUENT VIA AN ECE MECHANISM

We have carried out a study on the reduction of cefsulodin by classic polarography (CP), linear sweep voltammetry (LSV) and chronocoulometry with voltammogram integration. The experimental conditions were chosen so as to ensure the exclusive reduction of the adsorbed cefsulodin molecules in LSV. The reduction process takes place via the isonicotinamide substituent of cefsulodin. In acid media, cefsulodin yields a four-electron signal in classic polarography and two two-electron signals in voltammetry - this latter result, however, depends on the sweep rate used. This effect is accounted for on the basis of an ECE mechanism, and some criteria are put forward for the determination of the intermediate rate constant of such a mechanism. © 1990.