Voltammetric separation of dopamine and ascorbic acid with graphite electrodes modified with ultrafine TiO2

In this paper, a new method was introduced to separate dopamine and ascorbic acid simultaneously. When a graphite electrode was modified with nanosized TiO2 powder, it exerted little influence on the redox behavior of dopamine, but led to the anodic potential of ascorbic acid to move negatively which enlarged the anodic separation potential between dopamine and ascorbic acid to some extent. Better separation could be achieved with bare C and TiO2 modified electrode at higher scan rate. The catalytical ability of nanosized metal oxide on the voltammetric behavior of dopamine and ascorbic acid was discussed as well.