Spectrophotometric determination of plutonium III, IV, and VI concentrations in nitric acid solution

The determination of the concentration of various valency states of plutonium is desirable in various stages of the Plutonium/Uranium Recovery by EXtraction (PUREX) process for the effective separation and purification of plutonium. A method is optimized for the quantitative spectrophotometric determination of Pu(III), Pu(IV) and Pu(VI) existing separately or in mixed oxidation states in 1.5 M nitric acid medium. Molar absorption co-efficient (ε) for the major absorption peaks with baseline correction are evaluated. With these ε data a method is proposed for determining the molar concentration of each oxidation state. (author)