Inorganic sorbents in 99mTc generators

99mTc generators are largely based on the sorption principle, using 99Mo bonded to aluminium oxide. These generators possess a relatively low sorption capacity (20 to 30 mg of 99Mo per gramme of sorbent), which calls for the use of high specific activities of 99Mo if generators with sufficiently high activities are to be obtained. Sorption matrices on which increased 99Mo contents can be reached are therefore sought. A suitable matrix material is zirconium polymolybdate, where 99Mo directly embedded in the matrix is obtained by neutron irradiation in a reactor. A new gel generator of technetium was thus developed. With a view to achieving optimum 99mTc recovery from the generator, the structure of the molybdates was studied in dependence on the conditions of their preparation. The Zr-Mo xerogels were subjected to X-ray structure and infrared spectroscopic analysis and their radiation stability was investigated. Synergistic factors affecting the properties of the xerogels with respect to the 99mTc recovery are described. (author). 1 fig., 11 tabs., 19 refs