Introduction: Auger emitters are investigated for their application in radiotherapy. Among them, 103mRh can be produced from 103Ru.1 The most challenging task is to reach an effective separation between the radionuclides concerned. Separations of these two elements by liquid-liquid extraction2 or by distillation3 are already known. Nevertheless, the use of a chromatographic-type generator (103Ru/103mRh) would be more practical for widespread research use, and in particular in nuclear medicine services. The main objective is to find an ionic exchange resin able to separate these two elements efficiently. Methods: Several resins (Dowex 1x8 Cl-, Resin 1 Triskem®, Resin 2 Triskem®) have been considered to evaluate their capacity to separate Ru and Rh. Preliminary tests have been achieved. The conditions are batch experiments, [Ru]=[Rh]~10-5M. The elements were analyzed by ICP-OES or ICP-MS (initial and final concentrations) in order to establish the Kd values on the different resins tested. For the most promising resin, additional studies (influence of the raw material, repeatability, reproducibility) and column tests have been conducted. Results: Based on the preliminary results, Resin 2 Triskem® seems to be the most suitable candidate for Ru/Rh separation. More than 90% of Ru initially introduced is retained on the resin, and no Rh is retained. Age of Ru solutions has an impact on the speciation of Ruthenium and its retention on the resin. Discussion: Resin 2 Triskem® appears to be able to be used in the chromatographic-type generator (103Ru/103mRh). More studies need to be conducted to certify its potential, especially Ru breakthrough evaluation. (1) Filosofov and al. Potent Candidates for Targeted Auger Therapy: Production and Radiochemical Considerations. Nuclear Medicine and Biology 2021, 94–95, 1–19. (2) Al-Bazi and al. Extraction of Ruthenium Thiocyanate and Its Separation from Rhodium by Polyurethane Foam. Talanta 1984, 31 (3), 189–193. (3) Kurbatov and al. Isolation of Carrier Free Rhodium from Ruthenium Targets. Journal of Inorganic and Nuclear Chemistry 1961, 18, 19–23.