Influence of pH on hanging mercury drop electrode cyclic voltammetry with aspartic acid in acetate buffers

摘要

As the supporting electrolyte (acetate buffer) itself interacts with mercury, the Hg-acetate current is always superimposed on the Hg-amino acid interaction current. Hence whether ammo acid is present or not there will be the current of Hg-acetate leading to intercept on the current axis of the I_p vs [aspartic acid] plot. There are three processes deduced from Hg-amino acid solution interaction. They are process A, B and G. Process A is due to mercuric mercury complex formation, Hg~o+(asp)<->Hg~(2+) (asp) and process b is due to mercurous mercury complex formation, Hg~o+(asp)<->Hg~(2+) (asp). Process C is the result of mercury-acetate interaction. The peak potentials are shifted to less positive values with increasing pH.