SYNTHESIS OF NEW ADSORBENTS FOR MO AS AN RI GENERATOR

Technetium-99m is widely used in the world for the purpose of diagnosi s in nuclear medicine. The Tc-99m is obtained from the parent nuclide of Mo-99 adsorbed in a generator. Synthesis of Zr-based inorganic poly mer, which has extremely high adsorbability of Mo and is applicable to the Mo-99 product of low specific activity, was attempted. Five kinds of the precursors fbr Zr-based-polymer adsorbents were prepared by th e hydrolysis of ZrCl4 and the reactions between ZrCl4 and poly (vinyl alcohol), isopropyl alcohol, ethylene glycol or glycerol, These precur sors were converted into adsorbents by heating in Ar gas flow. Their s tructures were presumed from the pyrolysis behavior. Absorption capaci ties of Mo of these adsorbents were dependent on the number of Cl atom s bonded to Zr atom in the molecules. It was suggested that the adsorp tion of Mo to these adsorbents was proceeded by chemical reaction betw een two neighboring Zr-Cl bonds and MoO42-. The adsorbent prepared fro m ZrCl4 and isopropyl alcohol showed the highest adsorption capacity o f Mo (about 250 mg/g adsorbent) and (TC)-T-99m yield (about 80%) in el uant.