Studies on the nature of the reactions and species involved in potentiometric titrimetric determination of uranium

The species and reactions involved in the determination of uranium by the Davies and Gray method have been investigated through the behaviour of the various species when present alone or in various combinations in the reaction medium. The studies indicate the formation of Fe(II) and V(III) in the titration system. These two species appear easily prone to oxidation by the titration medium. Probable reasons for the negative bias found when the titration is not completed in the stipulated time period, and for the sharpening of the end-point by the presence of vanadium(IV), are discussed.