Charge and nature of technetium species produced in the reduction of pertechnetate by stannous ion. [/sup 99m/Tc]

By using a cation-exchange distribution technique, the net charge of the technetium species produced in the reduction of pertechnetate by stannous ion at ph equal to or less than 2 has been determined to be +2. The species carrying this charge is either the dihydroxy technetate (Tc(OH)/sub 2//sup 2 +/) ion or the oxotechnetate (TcO/sup 2 +/) ion. These species are hydrolysed to technetium dioxide dihydrate (TcO/sub 2/ . 2H/sub 2/O) at higher pH. The advantage of the ion-exchange distribution technique for these studies is that they can be done with carrier-free technetium rather than at the high concentrations required for the more conventional methods of ion-charge determination. The results, therefore, are more likely to be applicable to the situation existing in the routine preparation of Tc-99m radiopharmaceuticals.