Abstract

Attempts have been made to use Szilard Chalmers reaction to prepare ⁹⁹Mo and ⁹⁰Y in high specific activity. Experiments were carried out using irradiation of freshly prepared oxinate complexes of molybdenum and yttrium in the HOR reactor of Reactor Institute at TU Delft. The irradiated target was dissolved in dichloromethane and the radionuclides were separated by solvent extraction into aqueous phase. Detailed investigations on the effect of pH of aqueous solution, irradiation time and target amount was also carried out to optimize the enrichment factor and yield. The highest enrichment factor for ⁹⁹Mo was found to be around 200 with a yield close to 30%. In the case of ⁹⁰Y, solvent extraction method did not yield high enrichment factors. Slightly higher enrichment factors were achieved with ion exchange method. Studies were also carried out with yttrium oxide nano-powder. Speciation study of ⁹⁹Mo in the separated aqueous fraction showed it to be present as ⁹⁹MoO₄²⁻ ion. The results appear to be quite promising for large scale production of ⁹⁹Mo for medical applications.