Preparation and Surface Characterization of Cerium Dioxide for Separation of 68Ge/68Ga and Other Medicinal Radionuclides

The overall need for the preparation of new medicinal radionuclides has led to the fast development of new sorption materials, extraction agents, and separation methods. Inorganic ion exchangers, mainly hydrous oxides, are the most widely used materials for the separation of medicinal radionuclides. One of the materials that has been studied for a long time is cerium dioxide, a competitive sorption material for the broadly used titanium dioxide. In this study, cerium dioxide was prepared through calcination of ceric nitrate and fully characterized using X-ray powder diffraction (XRPD), infrared spectrometry (FT-IR), scanning and transmission electron microscopy (SEM and TEM), thermogravimetric and differential thermal analysis (TG and DTA), dynamic light scattering (DLS), and analysis of surface area. In order to estimate the sorption mechanism and capacity of the prepared material, characterization of surface functional groups was carried out using acid-base titration and mathematical modeling. Subsequently, the sorption capacity of the prepared material for germanium was measured. It can be stated that the prepared material is prone to exchange anionic species in a wider range of pH than titanium dioxide. This characteristic makes the material superior as a matrix in Ge-68/Ga-68 radionuclide generators, and its suitability should be further studied in batch, kinetic, and column experiments.

Automated summary

The development of new sorption materials, extraction agents, and separation methods is driven by the demand for new medicinal radionuclides. Inorganic ion exchangers, especially hydrous oxides, are commonly used for the separation of these radionuclides. Cerium dioxide, a competitive sorption material to titanium dioxide, was extensively studied in this research. The material was prepared and characterized using various techniques, and its sorption capacity for germanium was measured. The material showed a wider range of pH for anion exchange compared to titanium dioxide, making it a potential matrix in Ge-68/Ga-68 radionuclide generators.