Chromatographic separation of the theranostic radionuclide 111Ag from a proton irradiated thorium matrix

Abstract Column chromatographic methods have been developed to separate no-carrier-added 111 Ag from proton irradiated thorium targets and associated fission products as an ancillary process to an existing 225 Ac separation design. Herein we report the separation of 111 Ag both prior and subsequent to 225 Ac recovery using CL resin, a solvent impregnated resin (SIR) that carries an organic solution of alkyl phosphine sulfides (R 3 P = S) and alkyl phosphine oxides (R 3 P = O). The recovery yield of 111 Ag was 93 ± 9% with a radiochemical purity of 99.9% (prior) and 87 ± 9% with a radiochemical purity of 99.9% (subsequent to) 225 Ac recovery. Both processes were successfully performed with insignificant impacts on 225 Ac yields or quality. Measured equilibrium distribution coefficients for silver and ruthenium (a residual contaminant) on CL resin in hydrochloric and nitric acid media are reported, to the best of our knowledge, for the first time. Additionally, measured cross sections for the production of 111 Ag and 110m Ag for the 232 Th(p,f) 110m,111 Ag reactions are reported within.