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铅是环境、生命科学中一个重要的有毒元素。目前对生物样品中微量铅的分析方法主要是原子吸收光谱及阳极溶出伏安法。Aruscavaga 曾报道了~(210)Pb 同位素稀释亚化学计量法测定岩石中铅,但用该法测定生物样品中铅未见报道。此外,~(210)Pb 是天然放射性同位素,不易获得,而且半衰期长达19.4年,本身还带有子体~(210)Bi 等,使用不便。而我们用回旋加速器制得的无载体放射性同位素~(203)Pb 有适中的半衰期(52小时),无放射性废物处置问题,其主要γ射线279keV 便于检测,而且无载体~(203)Pb 的比活性比~(210)Pb 为高。这些优点无疑十分有利于同位索稀释亚化学计量法测定生物样品中微量铅。
Lead is an important toxic element in the environment and life sciences. At present, the analytical methods of trace lead in biological samples are mainly atomic absorption spectrometry and anodic stripping voltammetry. Aruscavaga reported ~ (210) Pb isotope dilution stoichiometry for the determination of lead in rocks, but the determination of lead in biological samples by this method has not been reported. In addition, ~ (210) Pb is a natural radioisotope that is not readily available and has a long half-life of 19.4 years and itself contains a daughter of ~ (210) Bi etc. for inconvenience. However, the carrier-free radioactive isotope 203 Pb we obtained from cyclotron has a moderate half-life (52 hours) with no radioactive waste disposal problem. The main γ-ray 279 keV is easy to detect and there is no carrier to 203 Pb ratio The activity is higher than ~ (210) Pb. These advantages are undoubtedly very conducive to isotope dilution of stoichiometry biological samples of trace lead.