Chemical purification of 111Ag from isobaric impurity 111Cd by solid phase extraction chromatography: a proof of concept study

Silver-111 (111Ag, t1/2 = 7.47 d) is a β− emitter suitable for targeted cancer therapy due to favourable decay properties. The production of no-carrier added 111Ag via Isotope Separation On-Line (ISOL) technique is being investigated at the Legnaro National Laboratories of the Italian Institute of Nuclear Physics (ISOLPHARM project). Stable Cadmium-111 (111Cd) is co-produced as isobaric contaminant, hence a chemical separation process must be developed to selectively harvest 111Ag. In this study, a chromatographic procedure employing the commercially available CL resin was investigated by using stable Ag+ and Cd2+. Results indicate that CL resin allows to efficiently separate Ag+ from Cd2+ and recover the former with high yields.