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天然存在的锝来源于铀矿中238U的自发裂变,或钼矿石中钼的中子俘获,绝对量极少。目前,环境中的锝来源于核试验及乏燃料后处理厂的排放等,到2008年,已有约1.6 PBq(2.5 t)的99Tc被释放到环境中。由于99Tc具有半衰期长,迁移速度快,易于从土壤进入植物等特点,环境样品中99Tc的分析日益受到重视。99Tc为纯β放射性核素,放化法分析环境样品中99Tc含量的难点在于,
The naturally occurring technetium comes from the spontaneous fission of 238U in uranium or the neutron capture of molybdenum in molybdenum, with very little absolute amount. At present, the environment of technetium is derived from nuclear tests and emissions from spent fuel reprocessing plants. By 2008, about 1.6 PBq (2.5 t) of 99Tc has been released into the environment. Because 99Tc has the characteristics of long half-life, fast migration rate and easy access from soil to plant, the analysis of 99Tc in environmental samples has been paid more and more attention. 99Tc as a pure beta radionuclide, radiochemical analysis of 99Tc in environmental samples of the difficulty is that,