Molybdenum Adsorption and Desorption Properties of Alumina with Different Surface Structures for 99 Mo/ 99 m Tc Generators

Abstract

The production of 99 Mo via a (n, γ) reaction is a simple and easy method and is advantageous from the viewpoints of nuclear proliferation resistance and waste management. However, the production of 99 m Tc solutions with heavy levels of radioactivity is difficult because the specific radioactivity of 99 Mo produced via this method is extremely low. Thus, it is necessary to develop a novel adsorbent with high Mo-adsorption efficiency. In this study, alumina (Al2O3), which is often used in medical 99 Mo/ 99 m Tc generators, was used as the Mo adsorbent. Al2O3 specimens were prepared with three types of starting powders and sintered at different temperatures; in addition, their Mo adsorption and desorption properties were evaluated. The results indicated that the Mo-adsorption properties are influenced by the crystal structure and the specific surface of the Al2O3. In addition, the basic chemical properties of the solution eluted from each developed Al2O3 specimen were within the limits given by the guidelines. Keywords: 99 Mo/ 99 m Tc generator, Alumina, Mo adsorption, Mo desorption 1. INTRODUCTION Medical imaging techniques using technetium-99 m (99 m Tc; T1/2 = 6 h) are used in approximately 80% of all nuclear medicine procedures, representing over 30 million examinations worldwide every year. 99 m Tc is most commonly used for radiopharmaceuticals in the field of nuclear medicine. 99 m Tc is generated by the decay of molybdenum-99 (99 Mo; T1/2 = 66 h). Japan is the world's third-largest consumer of 99 Mo after the United States of America and Europe and relies entirely on imports to meet its domestic demand.