Voltammetric study on ion transfer of uranium(VI) ion between aqueous and nitrobenzene phases in the presence of bis(diphenylphosphoryl)methane

The ion transfer of UO22+ ion across an aqueous(w)/nitrobenzene(NB) interface was investigated by ion-transfer polarography using an aqueous electrolyte dropping electrode. It vias found that the transfer of UO22+ from w to NE was facilitated by bis(diphenylphosphoryl)methane (BDPPM), and that the transfer reaction had irreversible characteristics. A potential generated at the UO(2)(2+)ion-selective electrode, which was prepared while referring to ion transfer data, revealed a reversible Nernstian response against the concentration of the UO22+ ion in an aqueous sample solution. The irreversible nature of the UO22+ transfer observed in the polarogram resulted from such slow processes involved in the ion transfer reaction as the adsorption/desorption of BDPPM or the UO22+-BDPPM complex at the w/NB interface. The feasibility of the electrolytic separation of uranium from neptunium and plutonium on the basis of a selective ion-transfer reaction is discussed.