Molybdenum-99 ( 99 Mo) Adsorption Profile of Zirconia-Based Materials for 99 Mo/ 99m Tc Generator Application

Technetium-99m ( 99m Tc) plays a major role in diagnostic nuclear medicine and has not yet been replaced with any other radionuclides. It is available through the 99 Mo/ 99m Tc generator. The use of low-specific-activity 99 Mo for 99 Mo/ 99m Tc generator application requires high adsorptive capacity sorbents. This study focused on the determination of 99 Mo adsorption capacity of several zirconia materials, namely monoclinic nanozirconia , orthorhombic nanozirconia , sulfated zirconia, and phosphated zirconia. These materials were synthesized by using the sol-gel method and characterized using FT-IR spectroscopy, X-ray diffraction (XRD), and scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM-EDS). The determination of 99 Mo adsorption capacity of these materials was carried out by soaking the materials in a Na 2 99 MoO 4 solution with pH of 3 and 7, at temperatures ranging from room temperature to 90 °C, for 1 and 3 hours. The results indicated that monoclinic nanozirconia has a 99 Mo adsorption capacity of 76.9 mg Mo/g, whereas orthorhombic nanozirconia , sulfated zirconia, and phosphated  zirconia have 99 Mo adsorption capacities of 150.1 mg Mo/g, 15.58 mg Mo/g, and 12.74 mg Mo/g, respectively. It appears that orthorhombic nanozirconia has the highest 99 Mo adsorption capacity among the synthesized materials and can be applied as a candidate material for the 99 Mo/ 99m Tc generator.