68Ga (T1/2 = 68 min) is used for molecular imaging in positron emission tomography. 68Ga decays via 1.92 MeV positron emission (89%) and electron capture (11%). Due to suitable half-life for radiolabeling and easy availability from radionuclide generator, interest in 68Ga labelled compound has increased.
The most convenient method of 68Ga production is usage of 68Ge → 68Ga radionuclide generator. Currently available commercial generators have number of disadvantages and need to be improved. The shortcomings are the usage of hydrochloric acid, large volumes of eluate and the presence of low-charge metal cations impurities, which prevent the formation of gallium complexes during labeling.
In this study the sorption behavior of Ge on ion-exchange resins in various solutions of oxalic and hydrochloric acids are carried out. The optimal scheme for efficient separation of germanium and gallium was also developed. The scheme is based on anion exchange resin and mixture of the acids C2H2O4 and HCl. Three generators 68Ge → 68Ga and two elution methods (direct and reverse) were tested. Further use of the tandem column will significantly improve the quality of the resulting product and will enable the selection of conditions for direct labeling.