Stable measurement of redox potential of aqueous solution using platinum electrode with continuous polishing tool

Ioka, Seiichiro; Iwatsuki, Teruki  ; Kato, Osamu*; Imakita, Tsuyoshi*

Performance test for redox potential measurement of solution was conducted using continuous polished and untreated Platinum working electrodes in under inert condition. The redox potential measured by polished electrode immediately shows steady value, and approximately coincides with the equilibrium value of redox reaction between HS and S. Then the redox potentials would be controlled by the equilibrium of the redox reaction. On the other hand, redox potential measured by untreated electrode was +0.2V higher than that measured by continuous polished electrode. The redox potential measured implies that the SO is dominant species in solution. Disagreement of redox potentials measured by polished and untreated electrodes may be caused by deactivation of platinum electrode of adsorption of sulfuric acid anions.