99mTc Generator — The Maintenance of High Elution Efficiency

Several protecting procedures were applied to ensure good operating performances of the universal ^99mTc generators based on fission produced ⁹⁹Mo. These procedures include the modifications of the adsorbent. Instead of 1 g of pure Al₂O₃ the adsorption of ⁹⁹Mo is carried out on the multicomponent adsorbent containing the mixture of either Al₂O₃ + SiO₂ or Al₂O₃ · Cu²⁺ + SiO₂. The protection by drying should ensure that the columns contain minimum of moisture during the growth period of ^99mTc. It was found experimentally that the best results are obtained when the ratio of alumina in the mixture was 15 ± 5 (wt.%) and content of copper 365 μg Cu²⁺/column. The comparison of efficiency and applicability of the used protecting procedures is also given.