This investigation is an application of the method involving determination of H AsO4, KIO3, KBrO3, KMnO4, and K2S2O8 as oxidants. The method is based on reduction of oxidants by hydrazine sulphate in different pHs, adding a measure excess of hydrazine to reduce the ox:« dant, then unreacted hydrazine oxidized by iodine dissolved in acceti acid. The liberated iodide was then potentiometrically titrated against Ag(l) using silver amalgam as the indicator elect- rode.