1996 年 45 巻 8 号 p. 511-514
Analysis of 99Tc in the environment have been interested because of a long term radioecological effect of 99Tc due to its long half-life. One of the problems on 99Tc analysis is a tracer since there is no stable isotope in Tc. Development of 99Tc determination by ICP-MS enables us to use 95mTc as a yield monitor. The radiochemical yield is evaluated by gamma spectrometry of 95mTc and 99Tc is determined by mass spectrometry without any in-terference by 95mTc tracer added to the sample. We produced 95mTc without 99Tc by an irradiation of metal Nb with 40MeV alpha particles using cyclotron. The 0.1 mm thickness Nb foil stacked 4 pieces was irradiated for 21 h at beam current of 1.5μC, dissolved in a mixture of HNO3 and HF, and 95mTc was isolated and purified chemically. No contamination of 99Tc was confirmed on 95mTc fraction.