The radiochemical separation of no-carrier-added cerium from proton irradiated lanthanum was studied by solvent extraction using DEE, TBP and
TPPO, the latter reagent being employed for the first time for separation of radiocerium from bulk of lanthanum. Distribution coefficients of cerium
and lanthanum were investigated as a function of equilibrium time and concentration of HNO3. A mixture of 0.05M K2Cr2O7 and 0.1M H2SO4
was used as an oxidizing agent to improve the separation efficiency of cerium. A comparative study of the three extractants released that DEE is
the best for separation of cerium from bulk of lanthanum oxide. The target was prepared by pressing. The production of 139Ce of high radionuclidic
purity and chemical purity via irradiation of lanthanum oxide target at MGC-20 cyclotron with protons of energy 14.5 MeV is described. The
experimental yield was found to be 153 kBq/µA·h