Polarography, hydrogen peroxide determination

The most useful application of polarography in biochemistry is the determination of oxygen. The reduction of oxygen proceeds in two steps at a mercury dropping electrode. In the first wave oxygen is reduced to hydrogen peroxide and in the second, more negative wave, the peroxide formed is reduced to water. 

Finally, among inorganic molecules, polarography can be used to determine oxygen, hydrogen peroxide, elemental sulfur, some sulfur oxides, and oxides of nitrogen, as well as some undissociated acids. 

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