Study of individual lanthanides separation using Dynamic ion exchange chromatography

The field of nuclear medicine and radiotherapy is showing an increased interest in radioisotopes. In particular, Lutetium-177 appears to be an ideal therapeutic radioisotope with suitable chemical properties and nuclear decay characteristics. 177Lu can be produced using a nuclear reactor either directly by the 176Lu(n, ɣ) →177Lu route or indirectly by the 176Yb(n, ɣ) → 177Yb(β-) → 177Lu route. The first route gives rise to Lu with a relatively low specific activity caused by the large amount of 176Lu which competes with 177Lu, thereby reducing radiotherapy efficiency. Therefore, the second route seems to be more promising resulting in 177Lu with a higher specific activity and high radiochemical purity. This method, however, requires a good separation of 177Lu from the unreacted Ytterbium-176.
The current study investigates the cold separation process of the heavy lanthanides (Lu3+, Yb3+) using dynamic ion exchange chromatography with 2–hydroxyisobytric acid (α-HIBA) and 1-Octanesulfonate (1-OS) as elution agents. The influence of α-HIBA, 1-OS concentrations as well as temperature, pH of eluent and stationary phases were studied. The developed methodology for cold Lutetium/Ytterbium separation is validated and by the investigation of the 177Lu/175Yb ratio.