“…The method of controlled-potential coulometric analysis has been applied to the oxidation of iron(II) (9), arsenic (III) (9,10), thallium(I) (3), and plutonium(III) (12) with 100% current efficiency at a platinum anode. With oxidations which involve reversible electrode couples, the potential of the working electrode determines the ratio of the amounts of oxidized and reduced forms that can exist in contact with the electrode, and current is forced to flow until such a ratio is reached.…”