Radionuclide purity of sup(99m)Tc sources obtained from imported and homemade generators

In eluates from 99Mo/sup(99m)Tc generators by Amersham Ltd., England, the ratio of activities of the most important long-lived contaminating emitters 134Cs and 60Co to the activity of sup(99m)Tc at the time of elution is of the order of 10-8 and the ratio of 99Mo activity to sup(99m)Tc activity is of the order of 10-7. The ratio of 134Cs and 60Co activities in eluates from 99Mo/sup(99m)Tc generators manufactured in Poland in 1980 to the activity of sup(99m)Tc at the time of elution is of the order of 10-5 and 10-6, resp. These values still do not exceed the limit given by beneath our standard which states that the activity of other radionuclides (excluding 131I and 132I) must not be greater than 0.01% of the total activity in the sup(99m)Tc eluate. In solutions of sodium sup(99m)Tc-pertechnetate from an extraction generator by the Institute of Nuclear Research in Rez a measurable 134Cs activity was found in some samples only, the ratio of 60Co/99Tc activities at the time of elution is in the majority of samples of the order of 10-9 or lower and the ratio of 99Mo/sup(99m)Tc activities is of the order of 10-7. The 131I content was assessed in most specimens: the activity related to the reference date is well below the limit given by our standard (131I/99Tc<0.05%). (author)