DESCRIPTION AND INTERPRETATION OF THE EXPONENTIALLY SHAPED WAVES YIELDED IN THE POLAROGRAPHIC-REDUCTION OF CEPHALOSPORINS AT HIGH-CONCENTRATIONS IN ACID-MEDIA

At concentrations above 2 × 10-4 M and acid pH values, cefazolin and cefmetazole yield reduction waves in which the current varies exponentially with the potential throughout and the diffusion plateau is reached abruptly. On the basis of consideration of the reduction product, this behaviour is assumed to be governed by an irreversible electron transfer and the adsorption of the products, which is negligible compared with that of the reactants. We have used a mass transfer equation based on the diffusion-layer approximation and assumed that the molecules are adsorbed immediately once they have reached the electrode surface by diffusion. © 1990.