Uranyl selective electrode based on organophosphorus compounds

A comparative study on the potential functions of different membrane components showed that the combination of tri-n-butyl phosphate, tri-n-octylphosphine oxide, and sodium tetraphenylborate in the PVC matrix gave the best full Nernstian response (59 mV/decade) and it gave nearly the same potential behavior among uranyl chloride, nitrate, and sulfate bathing solutions. Due to the high affinity with uranyl ions, the membrane containing tri-n-octylphosphine oxide can be responsive to both cations and anions depending on the concentrations of the bathing solutions. Incorporation of sodium tetraphenylborate was found necessary for obtaining permselectivity of the cations. Monovalent cations were regarded as permeating species for the membrane. 3 figures, 3 tables.