Redox kinetics of adriamycin adsorbed on the surface of graphite and mercury electrodes.

Kinetics of the surface redox reactions of adriamycin (doxorubicin hydrochloride) adsorbed on paraffin-impregnated graphite electrode (PIGE) and on mercury electrode is measured by square-wave voltammetry. In 0.9 mol/L KNO3 buffered to pH 4.65, the standard electrode reaction rate constants of the first quinone/hydroquinone redox couple (see Scheme 2) on PIGE and mercury are k(s1)=49+/-12 s(-1) and k(s1)=147+/-36 s(-1), respectively. Under the same conditions, the standard rate constant of the second redox couple on the PIGE is smaller than 4 s(-1) and the electron transfer coefficient of the reduction is alpha2=0.35.