同位素标记在汞的生物地球化学研究中的应用

Applications of isotopic labeling technique in the studies of mercury biogeochemistry: A review

汞是一种可以长距离迁移的全球性污染物,无机汞进入水生环境可以转化为高神经毒素的甲基汞,通过在食物链中发生生物积累和生物放大作用,并最终威胁人体健康。同位素具有示踪特性,在环境中人为添加放射性汞同位素或单一富集稳定汞同位素标记的单质汞或汞化合物,研究汞同位素的行为特征可以揭示生态环境中汞的生物地球化学行为。汞同位素标记技术的发展和应用为环境中汞的迁移和转化研究,尤其复杂环境中汞的形态转化和归趋提供了有效手段。本文介绍了放射性汞同位素标记技术和单一富集稳定汞同位素标记技术的原理,汞同位素标记技术在环境样品和生物样品的汞形态分析,陆地系统中土壤-植物-大气之间汞的迁移与转化,水生生态系统大气沉降汞的迁移和转化、汞的甲基化作用及形态汞的生物富集等领域的主要研究成果,并展望了汞同位素标记技术的应用前景。

As a global pollutant, mercury （Hg） can be transported for a long distance in atmos- phere. Methyl-mercury （MeHg） , an extremely toxic organic form of Hg formed by the methyla- tion from inorganic Hg in aquatic environment, can be bin-accumulated and bin-magnified along food chains, potentially threatening human health. Isotopes can trace the behaviors of elements in the environment. Adding Hg isotope to the environment or using Hg isotopic labeling technique is a powerful tool for the studies of Hg biogeochemical behaviors, including the transportation and transformation of Hg in the environment. This paper reviewed the basic theory of Hg isotopic la- beling technique, the applications of this technique in sample Hg species analysis, and the Hg transportation/transformation in soil-plant-atmosphere system and in aquatic ecosystem, and pros- pected the applications of Hg isotopic labeling technique in the studies of Hg environmental geo- chemistry.