Results of regular study on radionuclidic purity of 99mTc obtained from 99Mo--99mTc generators

A total of 39 99mTc eluates obtained from 9 99Mo--99mTc generators delivered by The Radiochemical Centre Amersham during one year was studied with regard to their radionuclide purity. Using a Ge(Li) spectrometer the contaminants 60Co, 103Ru, 131I, 134Cs, 140Ba, 140La and 188Re were found in 99mTc-eluates with average levels ranging from 2.9 X 10(-3) to 2.8 X 10(-1) per cent of 99mTc activity. The additional total body absorbed dose caused by these contaminants, as calculated from their average content in 99mTc eluates, was less than 1% of the dose due to 99mTc pertechnetate.