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

Abstract

Technetium-99m (^99mTc) plays a major role in diagnostic nuclear medicine and has not yet been replaced with any other radionuclides. It is available through the ⁹⁹Mo/^99mTc generator. The use of low-specific-activity ⁹⁹Mo for ⁹⁹Mo/^99mTc generator application requires high adsorptive capacity sorbents. This study focused on the determination of ⁹⁹Mo 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 ⁹⁹Mo adsorption capacity of these materials was carried out by soaking the materials in a Na₂⁹⁹MoO₄ 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 ⁹⁹Mo adsorption capacity of 76.9 mg Mo/g, whereas orthorhombic nanozirconia, sulfated zirconia, and phosphated zirconia have ⁹⁹Mo 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 ⁹⁹Mo adsorption capacity among the synthesized materials and can be applied as a candidate material for the ⁹⁹Mo/^99mTc generator.