We developed a new analysis method of hypochlorite using a reduction wave observed at about 600 mV
vs. Ag/AgCl, after the potential sweep direction was switched from anodic to cathodic. The measurement was performed using mirror-polished pure platinum as a working disk electrode. For the reduction wave observed at a switching potential of 1200 mV
vs. Ag/AgCl, the cathodic peak current and the concentration showed a good linear relationship at a concentration range of 0.2∼6.0 mg dm
−3. The relative standard deviation (
n = 3) of the reduction wave gave a good result of RSD<0.02. This electrode reaction was investigated by varing the pH value, the switching potential, and the sweep rate. As a result, it is considered that the cathodic current can be attributed to the reduction of HClO, which is formed by shifting the pH to the acidic direction based on water electrolysis during anodic polarization.
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