817—Application of short controlled drop-time polarography to the study of superoxide ion dismutation in aqueous solutions

A short controlled drop-time mercury electrode was utilized to generate the superoxide ion, O 2 − , in aqueous solutions and to study the dismutation processes of this ion. In particular, by the method of the catalytic currents, it was possible to measure the activity of superoxide dismutases, a class of metallo-enzymes present in aerobic cells. The use of this electrode minimizes the contribution of the spontaneous dismutation of the O 2 − to the limiting currents and, as a consequence, it makes enzyme activity measurements possible down to physiological pH values. The advantages with respect to other physicochemical methods are discussed.