ISOTOPE-EXCHANGE BETWEEN 12-MOLYBDOCERATE(IV) AND SODIUM MOLYBDATE MO-99 IN AQUEOUS-MEDIA

12-molybdocerate(IV) gel labelled with Mo-99 has been prepared via iso tope exchange between a column of inactive molybdate matrix and a mobi le solution of Mo-99-sodium molybdate(VI) in 0.1 mol . dm(-3) HNO3. Th e composition and nature of the reaction mixture, concentration of Mo( VI) in the reactants, reaction temperature and/or drying temperature o f the gel matrix on the exchange yield of Mo-99 and time of reaction a re explored using the batch equilibration and/or the chromatographic c olumn methods. The obtained material is evaluated for use in preparati on of elution-type Mo-99-Tc-99m generators.