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Research of marine geochemical cycles of novel trace metals.

新型微量金属海洋地球化学循环研究。

基本信息

批准号：
13304045
负责人：
OBATA Hajime
金额：
$ 32.95万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2004
项目状态：
已结题

项目摘要

In order to understand the biogeochemical cycles in the ocean, we investigated the distributions and behaviors of the novel trace metals in the ocean.Firstly, the global distribution of silver, one of the novel trace metals, was studied from the Bering Sea to the Southern Ocean. The distribution was analyzed with a "pipe model" to reveal the biogeochemical process of silver in the ocean. Judging from the elevated silver concentrations in high-latitude regions, silver in the surface water is mainly supplied via vertical mixing from mid-water.Secondly, a determination method of platinum in natural waters was established by combining anion-exchange resin concentration method and isotope-dilution inductively coupled plasma mass spectrometry (ID-ICPMS). By determining platinum in the estuary of Tokyo Bay with this ID-ICPMS method, it is shown that platinum is scavenged at the estuary region vigorously. The results were also compared with those by cathodic stripping voltammetry(CSV). The lower platinum concentrations with CSV method imply that platinum is complexed strongly with organic compounds in the urban rivers. To estimate the sources of platinum into Tokyo Bay, the rain water and rural river water were analyzed with the ID-ICPMS method. The platinum concentrations in both waters were so low that both waters cannot be the main source for Tokyo Bay. Anthropogenic input from urban areas and (or) dissolution of particulate matter in the estuary are thought to elevate the platinum concentrations in Tokyo Bay.In the open ocean, the seawater samples collected around the Japan Trench areas were analyzed with this ID-ICPMS method. The vertical profile of platinum shows a quasi-nutrient type, ranged from 0.3 to 1 pM, in this station. Lateral transport of lithogenic materials, indicated from previous sediment trap experiments, may affect the elevated platinum concentrations in deep waters.

为了了解海洋中的地球化学循环，我们研究了海洋中新痕量金属的分布和行为，首先研究了从白令海到南大洋的新痕量金属之一银的全球分布。用“管道模型”分析了银在海洋中的分布，揭示了银在海洋中的地球化学过程。从高纬度地区银浓度升高的情况来看，地表水中的银主要由中层水垂直混合提供。其次，建立了阴离子交换树脂富集-同位素稀释电感耦合等离子体质谱法（ID-ICPMS）测定天然沃茨中铂的方法。通过测定东京湾河口的铂与此ID-ICPMS方法，它表明，铂在河口区清除积极。并与阴极溶出伏安法（CSV）进行了比较。CSV法测得的较低的铂浓度表明，城市河流中铂与有机化合物的络合作用较强。为了估算流入东京湾的铂的来源，用ID-ICPMS方法分析了雨水和农村河水。这两个沃茨中的铂浓度都很低，因此这两个沃茨不可能是东京湾的主要来源。东京湾的铂浓度是由于城市地区的人为输入和（或）河口颗粒物的溶解而升高的。在开阔海域，采用ID-ICPMS方法对日本海沟附近的海水样品进行了分析。铂的垂直剖面显示出准营养型，范围从0.3到1 pM，在这个站。横向运输的成岩物质，从以前的沉积物捕集实验表明，可能会影响铂浓度升高，在深沃茨。