新的痕量同位素示踪剂在全球变化研究中的应用  

Application of New Trace Isotope Tracer to Global Change Research

作　　者：宋金明[1] 李凤业[1] 李学刚[1] 李宁[1] 

机构地区：[1]中国科学院海洋研究所海洋生态与环境科学重点实验室,山东青岛266071

出　　处：《海洋科学进展》2002年第3期90-95,共6页Advances in Marine Science

基　　金：国家杰出青年科学基金--近海沉积物-海水界面化学过程与生源物质循环(49925614);中国科学院创新重大项目--近海碳循环过程研究(KZCX1-SW-01-08)资助项目

摘　　要：最近,用高精度多通道电感耦合等离子体质谱仪测定某些过渡金属,如Mo,Fe,Cu,Zn等同位素的组成,表明它们可作为全球变化研究中生物地球化学过程的示踪剂。现有的研究文献表明,Mo的同位素可用于古氧化还原环境研究,初步结果显示,海水中δ97/95Mo的变化与海洋有氧与缺氧沉积物有直接的关系,可记录缺氧沉积物的来源,以此为基础,可用δ97/95Mo的收支来估算从陆地进入海洋中Mo的通量和全球Mo同位素的收支;Fe同位素在一定程度上控制着海洋生物生产力的水平,其丰度也对气候变化有影响,但生物与非生物过程都可引起铁同位素的分馏,其δ56/54Fe的变化都可达1‰,所以Fe同位素不能单独用来界定地质记录的Fe参与的过程是生物还是非生物控制;Cu,Zn的同位素也被用来研究生物地球化学过程的示踪剂,但目前报道不多。综述了这一领域的主要进展,集中阐述了同位素示踪样品的制备、纯化与测定方法、同位素在海洋环境变化研究中的应用,最后提出了这一领域可能的发展方向。Highprecision isotope composition determination results using multichannel inductive coupling plasma mass spectrometer (MCICPMS) have indicated that some transition metal isotopes such as Mo, Fe, Cu and Zn can be taken as the biogeochemical tracers for global change research. It is shown from the available study results that the Mo isotope can be used for the peleoredox environemnt studies, the change in δ97/95 Mo in seawater is related to the oxic and anoxic sediments in the ocean and can record the origin of anoxic sediment, so the budget of δ97/95 Mo can be used to estimate the Mo continental flux into the ocean and the global Mo isotope budget. Fe isotopes play a controlling role in marine biological productivity level and their abundance in seawater has a substantial effect on the climate changes, but the Fe isotope fractionations might result from both bioprocess and abioprocess and the changes in δ56/54 Fe can be up to 1 ‰, so Fe isotopes only cannot be used to distinguish between the abiotic and biotic Fe processes in the geologic records. The Cu and Zn isopopes are also used as biogeochemical tracers, but the reported researches are less. In this paper, the main advances in this field are summarized with particular emphasis on the preparation, purification and determination method of isotope tracer sample and the isotope application to the sutdy on marine environmental changes, and the potential developing directions in this research field are also presented.

关 键 词：同位素示踪剂 过渡金属 全球变化 生物地球化学 气候变化 钼同位素 

分 类 号：P467[天文地球—大气科学及气象学] P593