Mass-independent fractionation of even mercury isotopes  

作　　者：Hongming Cai Jiubin Chen 

机构地区：[1]State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China [2]University of Chinese Academy of Sciences, Beijing 100049,China

出　　处：《Science Bulletin》2016年第2期116-124,共9页科学通报（英文版）

基　　金：supported by the Natural Science Foundation of China(41273023;U1301231);the National Basic Research Program of China(2013CB430001);the Strategic Priority Research Program(XDB05030302);the‘‘Hundred Talent’’Project of Chinese Academy of Sciences and SKLEG

摘　　要：Practically all physical, chemical, and biologi- cal processes can induce mass-dependent fractionation of mercury （Hg） isotopes. A few special processes such as photochemical reduction of Hg（Ⅱ） and photochemical degradation of methylmercury （MeHg） can produce mass- independent fractionation （MIF） of odd Hg isotopes （odd- MIF）, which had been largely reported in variable natural samples and laboratory experiments, and was thought to be caused by either nuclear volume effect or magnetic isotope effect. Recently, intriguing MIF of even Hg isotopes （even- MIF） had been determined in natural samples mainly related to the atmosphere. Though photo-oxidation in the tropopause （inter-layer between the stratosphere and the troposphere） and neutron capture in space were thought to be the possible processes causing even-MIF, the exact mechanism triggering significant even Hg isotope anomaly is still unclear. Even-MIF could provide useful information about the atmospheric chemistry and related climate changes, and the biogeochemical cycle of Hg.Practically all physical, chemical, and biological processes can induce mass-dependent fractionation of mercury(Hg) isotopes. A few special processes such as photochemical reduction of Hg(II) and photochemical degradation of methylmercury(Me Hg) can produce massindependent fractionation(MIF) of odd Hg isotopes(oddMIF), which had been largely reported in variable natural samples and laboratory experiments, and was thought to be caused by either nuclear volume effect or magnetic isotope effect. Recently, intriguing MIF of even Hg isotopes(evenMIF) had been determined in natural samples mainly related to the atmosphere. Though photo-oxidation in the tropopause(inter-layer between the stratosphere and the troposphere) and neutron capture in space were thought to be the possible processes causing even-MIF, the exact mechanism triggering significant even Hg isotope anomaly is still unclear. Even-MIF could provide useful information about the atmospheric chemistry and related climate changes, and the biogeochemical cycle of Hg.

关 键 词：Mass-independent fractionation Evenmercury isotopes Processes producing even-MIF Mechanisms triggering even-MIF SELF-SHIELDING Neutron capture 

分 类 号：TQ028[化学工程] O614.243[理学—无机化学]