Investigation of the kinetic behaviour of captopril followed by A.C. polarography

This paper clarifies the adsorption mechanism of 1-[(2S)-3-mercapto-2-methyl-1-oxopropyl]-L-proline (CPT) on DME. Some characteristic features of CPT adsorption, previously followed by cyclic voltammetry (CV), have been investigated to give more precise information about some electrochemical constants by alternating current polarography (ACP). The first harmonic ACP was considered a suitable tool for obtaining electrochemical parameters of surface-confined reactions. The entity and sign of the molecular interaction parameter (g), the thermodynamic constant of adsorption (Kads), the extrapolated apparent electron rate constant (Kextsh), the saturation concentration (Co), maximum surface density (Γt)etc. have been determined. The values of some of these electrochemical parameters, found in a previous paper, were confirmed.