Analytical applications of the determination of hexacyanoferrate(III) with ascorbic acid : Determination of hydrogen peroxide,peroxydisulphate and their mixtures

Hydrogen peroxide can be determined by reaction with excess of alkaline hexacyanoferrate(III), the excess being titrated with ascorbic acid. Peroxydisulphate is determined by reaction with hexacyanoferrate (II) in acidic medium, the hexacyanoferrate(III) formed being titrated with ascorbic acid. To determine hydrogen peroxide and peroxydisulphate in the presence of each other, two titrations are needed ; the results arc readily calculated.