Determination of the equilibrium and kinetic parameters for the surface-redox reaction of hydroquinone moiety of adsorbed adriamycin by means of numerical simulation of d.c. voltammogram

Electrochemical equilibrium and kinetic parameters for a redox reaction caused by the hydroquinone moiety of adriamycin adsorbed on a pyrolytic graphite electrode have been determined by means of a numerical simulation of the quasi-reversible d.c. voltammograms using a theory regarding a two-step one-electron surfaceredox reaction, since the electron-transfer rate constant is so small that the reversible d.c. wave can not be obtained and an analysis by a.c. voltammetry is difficult. The voltammogram was also analyzed from the viewpoint of a one-step two-electron surface-redox reaction mechanism taking into account the interaction parameters between adsorbed molecules. The analyses in terms of both mechanisms mentioned above reveal that the redox system considered here occurs through a two-step process.