The Pt|Hg|Hg2Ox|Graphite (Ox = oxalate ion) electrode was studied using NaClO4 as the support electrolyte. Preliminary experiments were carried out using NaNO3 as support electrolyte, following the same methodology as the previous work, and it was verified that there was a decrease in the electrode sensitivity over its usage time. In order to understand the behavioral difference of the electrode in NaClO4 and NaNO3 media, experiments were carried out to obtain potential vs time curves to verify the behavior as a function of time and also in different ionic media. The surface morphology of the sensor pellet used in NaNO3 media presented alteration, which suggests that this media favors reactions on the pellet surface when it comes into contact with the solution.
electrode of the second kind; oxalate; perchlorate; nitrate
