Bergquist Bridget A, Blum Joel D
Department of Geological Sciences, University of Michigan, 1100 North University Avenue, Ann Arbor, MI 48109, USA.
Science. 2007 Oct 19;318(5849):417-20. doi: 10.1126/science.1148050. Epub 2007 Sep 13.
Mercury (Hg) isotopes can be used as tracers of Hg biogeochemical pathways in the environment. The photochemical reduction of aqueous Hg species by natural sunlight leads to both mass-dependent fractionation (MDF) of Hg isotopes and mass-independent fractionation (MIF) of the odd-mass isotopes, with the relation between the MIF for the two odd isotopes being distinct for different photoreduction pathways. Large variations in MDF and MIF are observed in fish and provide new insights into the sources and bioaccumulation of Hg in food webs. MIF in fish can also be used to estimate the loss of methylmercury via photoreduction in aquatic ecosystems.
汞（Hg）同位素可作为环境中汞生物地球化学途径的示踪剂。天然阳光对水体中汞物种的光化学还原会导致汞同位素的质量依赖分馏（MDF）和奇质量同位素的质量非依赖分馏（MIF），不同光还原途径下两种奇同位素的MIF之间的关系各不相同。在鱼类中观察到MDF和MIF存在很大差异，这为食物网中汞的来源和生物积累提供了新的见解。鱼类中的MIF还可用于估计水生生态系统中甲基汞通过光还原的损失。
