Mechanism of 99 Mo adsorption and 99m Tc elution from zirconium-based material in 99 Mo/ 99m Tc generator column using neutron-irradiated natural molybdenum Rohadi Awaludin • AdangHardi Gunawan • Hotman Lubis • Sriyono • Herlina • Abdul Mutalib • Akihiro Kimura • Kunihiko Tsuchiya • Masakazu Tanase • Masahiro Ishihara Received: 22 August 2014 / Published online: 2 November 2014 Ó Akade ´miai Kiado ´, Budapest, Hungary 2014 Abstract The 99 Mo adsorption and 99m Tc elution mechanism were investigated using SEM–EDS to analyze the elemental composition of the adsorbent surfaces. From the changes of element composition, it was found that molybdate ions were adsorbed into the adsorbent by ion exchange with Cl - ion in the material. It was also revealed that 99m Tc can be eluted in high oxidation state since the 99m Tc in lower oxidation state easily made coordination bonds with other elements in the adsorbent. Keywords Adsorption mechanism Á 99 Mo/ 99m Tc radionuclide generator Á Neutron-irradiated natural molybdenum Á Oxidizing agent Introduction Technetium-99m ( 99m Tc) is widely used in diagnostic nuclear medicines [1]. At present, most of 99m Tc is produced from fission product molybdenum ( 99 Mo) which has some diffi- culties in the production process such as fission product han- dling and radioactive waste management. 99m Tc actually can be obtained from 99 Mo in neutron-irradiated molybdenum [2]. This method offers the advantages of being easy to obtain the target of molybdenum and requires relatively simple facility since it does not process fission product radionuclides. However, 99 Mo in irradiated natural Mo has a low specific radioactivity so that adsorbent with high adsorption capacity is required in column generator preparation. Several materials have been developed as the adsorbent [3–5]. A 99 Mo/ 99m Tc generator column using zirconium-based material (ZBM) has been prepared and studied. The material is hard enough and not easily broken during Mo adsorption and 99m Tc elution. The objective of this study is to investigate the adsorption mechanism of Mo in the material and the elution of the 99m Tc from the materials. It is expected that the adsorption capacity and the elution yield of 99m Tc can be increased based on the results of this study. Experimental Zirconium-based material was prepared by zirconium (IV) chloride, propanol and tetrahydrofuran (Sigma-Aldrich). ZrCl 4 and propanol were dissolved and stirred in THF. Addition of water to the solution resulted in a fragile material. The material was grinded and sieved, resulting in 10–20 mesh of particles. The particles were then treated by tetraethyl orthosilicate (TEOS) for increasing the hardness. Adsorption of 99 Mo to the material was performed using molybdate solution at temperature of 90 °C for 3 h. The molybdate solution was obtained by neutron-irradiation of natural molybdenum(VI) oxide in G.A. Siwabessy Reactor of National Nuclear Energy Agency of Indonesia. The radioactivity of 99 Mo adsorbed in the material and 99 Mo remained in the solution was measured using Dose Cali- brator of AtomLab 100. R. Awaludin (&) Á A. Gunawan Á H. Lubis Á Sriyono Á Herlina Á A. Mutalib Center for Radioisotope and Radiopharmaceutical, National Nuclear Energy Agency of Indonesia, Serpong, Indonesia e-mail: rohadi_a@batan.go.id A. Kimura Á K. Tsuchiya Á M. Ishihara Neutron Irradiation and Testing Reactor Center, Oarai Research and Development Center, Japan Atomic Energy Agency, Ibaraki, Japan M. Tanase Chiyoda Technol Corporation, Shizuoka, Japan 123 J Radioanal Nucl Chem (2015) 303:1481–1483 DOI 10.1007/s10967-014-3606-z