Electrometric titrations of Cr(VI), Mn(IV), V(V), Co(III) and U(VI) with a standard iron(II) solution in alkaline media containing hexitols

Direct and indirect potentiometric, bipotentiometric and biamperometric titrations with a standard iron(II) solution are described for some inorganic compounds in alkaline media containing hexitols (mannitol, dulcitol and sorbitol). The optimal conditions for titrations based on the Cr(VI) → Cr(III), Mn(IV) → Mn(III) → Mn(II), V(V) → V(IV), Co(III) → Co(II) and U(VI) → U(IV) systems are discussed. Of the hexitols studied, sorbitol has the greatest effect on the value of the redox potential of the Fe(III)/Fe(II) system; the E_f° value is about —1.10 V vs. SCE.