Polarographic Investigation of Dissolved Oxygen in Nonaqueous Solvent

In a common aprotic solvent, the dissolved oxygen is reduced to superoxide, and then to peroxide with tetraalkylammonium salt as the supporting electrolyte. With alkali metal ion as the supporting electrolyte, it is reduced further to form the third wave. All of these waves are controlled by the successive chemical reaction; namely if the products due to the successive reaction are stable, the reduction potential shifts to more positive direction. When the solvated ion of the supporting electrolyte is small, it forms stable complex with oxygen radicals, hence the reduction waves shift to positive potentials.