Evaluación de nanomateriales SiO2-TiO2 para el desarrollo y optimización del Generador 99Mo/99mTc en Medicina Nuclear

The 99mTc, radionuclide used for diagnosis and therapy in nuclear medicine, is commercially produced by radioactive decay of the 99Mo, 235U fission product. In order to reduce the import dependence of the 99Mo fission product, a number of alternatives have been proposed for the production of this radionuclide. One of the options available in the short term is the neutron activation of 98Mo in a nuclear reactor via the nuclear reaction 98Mo (?, ?) 99Mo and the parallel development of new materials with retention capacities of the parent radionuclide 99Mo higher than those that offer commercially the available solids; the two technologies together will allow the development of low or medium activity 99Mo/99mTc generators via neutron activation based on adsorbent nanomaterials with high fixation capacity. In this research work were synthesized and characterized simple oxides TiO2, SiO2 and their mixture in different proportions were use as adsorbent matrices in the preparation of 99Mo/99mTc generators where 99Mo was produced by neutron activation in the Triga Mark III reactor of the ININ. The synthesis of the nanomaterials was carried out by the sol-gel method using alkoxides as precursors, the resulting solids were characterized using techniques such as Scanning Electron Microscopy (SEM) for morphological analysis and particle size and Physical Adsorption of Nitrogen (BET) to obtain the specific surfaces. The retention capacity of Mo(VI) in the simple and mixed oxides was determined by the batch equilibrium method using the radioactive tracers technique and by saturation of the solid with MoO42− ions. The experimental results indicated that the capacity to retain molybdate ions is 37 mg Mo/g for TiO2 and 8.0 and 5.0 mg Mo/g for mixed oxides. For the SiO2 irrelevant values were obtained therefore it is not an alternative for the retention of Mo (VI) to a high degree. Due to the fact that TiO2 showed a better affinity for molybdenum, preliminary tests were also carried out on chromatographic columns filled with this oxide in order to prove its operation as a 99Mo/99mTc generator. These preliminary tests showed that all 99Mo remain fixed in the column while 99mTc is eluted by passing a 0.9% NaCl saline solution.