誘導結合プラズマ質量分析法による⁹⁹Tc分析のための^95mTcトレーサ製造

抄録

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.