Metal-Metal Oxide pH Sensor: the Effect of Anions and Aeration on pH Measurements

Abstract This work examines the electrochemical growth of iridium oxide electrodes for use as a pH sensor and further evaluates the usefulness of these probes in a variety of solutions with sulfur-containing anions. Electrodes were grown and calibrated according to reports in the literature and exposed to sulfate-, sulfite-, bisulfite-, and thiosulfate- containing solutions in various concentrations. No effect of changes in sulfate and sulfite ion concentration were observed, however, significant changes in the calibration behavior of the electrodes was observed after the exposure to the solutions with bisulfite and thiosulfate ions.