VOLTAMMETRIC BEHAVIOR OF 2-MERCAPTOPYRIMIDINE AT A SILVER ELECTRODE

Electrochemical characteristics of 2-mercaptopyrimidine (MPD) have bee n studied by linear scan voltammetry at a silver disk electrode (AgE). It was found that at appropriate potentials MPD can adsorb on and int eract with the electrode to form an insoluble silver salt on the surfa ce. As the potential is made more negative two cathodic peaks appear a t -0.66 V and -1.28 V, respectively. The peak at -0.66 V is attributed to the reduction of the sparingly soluble silver compound of MPD, and the other to the reduction of MPD to pyrimidine, which was confirmed by capillary electrophoresis. The deposition/stripping behavior of MPD is discussed and possible mechanisms are proposed. Additionally, the influence of some surfactants and halides on the shape and height of t he stripping peaks was determined. It was observed that cationic surfa ctants such as cetylpyridinium bromide and hexadecyltrimethylammonium bromide can dramatically increase the peak height and decrease the pea k width of the peak at -0.66 V.