Some remarks on 99Mo-sup(99m)Tc generator kinetics

Attention is drawn to some erroneous and incomplete pieces of information on 99Mo-sup(99m)-Tc generator kinetics published in the literature. The assumption that sup(99m)Tc is eluted completely from the generator leads to the incorrect sup(99m)Tc activity-time curve plotted in some papers. It is shown that the time at which sup(99m)Tc activity in the generator reaches the maximum value depends on the efficiency of 99Tc separation. The expression derived by authors allows the prediction of sup(99m)Tc activity available in the second separation performed several hours after the previous separation. (orig.)