Adsorption of Eu(III) on a Heterogeneous Surface Studied by Time-Resolved Laser Fluorescence Microscopy (TRLFM)
Adsorption of Eu(III) on a Heterogeneous Surface Studied by Time-Resolved Laser Fluorescence Microscopy (TRLFM)
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DOI：
10.1021/es8024287
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发表时间：
2009-03-15
影响因子：
11.4
通讯作者：
Tanaka, Satoru
中科院分区：
文献类型：
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作者：
Ishida, Keisuke;Kimura, Takaumi;Tanaka, Satoru
时间分辨激光荧光显微镜（TRLFM）是同时研究荧光团的强度、位置、类型和周围化学环境的有用工具。在这项研究中，我们证明了TRLFM在自然非均相表面上吸附Eu（III）的适用性。在Makable花岗岩及其组分（黑云母、斜长石、钾长石和石英）表面观察到不同的Eu（III）吸附种类。Eu（III）在黑云母、斜长石和石英上均质吸附，在钾长石上均质吸附。吸附Eu（III）的荧光衰减率直方图表明，Eu（III）荧光的有效猝灭可能是由于Eu（III）与表面相互作用或在表面形成多核羟基Eu（III）。Eu（III）在黑云母上有1种，在斜长石和钾长石上有2种。Eu（III）在花岗岩表面的吸附高度不均匀。花岗岩表面不同区域的TRLFM测量结果显示，Eu（III）具有不同的荧光衰减率。对比矿物组分的荧光衰减直方图，发现Eu（III）明显吸附在长石族上。还发现Eu（III）以外球配合物的形式吸附在花岗岩的蚀变矿物上。
Time-resolved laser fluorescence microscopy (TRLFM) is a useful tool to simultaneously investigate the intensity, location, type, and surrounding chemical environment of a fluorophore. In this study, we demonstrated the applicability of TRLFM for the adsorption of Eu(III) on a natural heterogeneous surface. Different adsorption species of Eu(III) were observed on the Makable granite surface and its constituents (biotite, plagioclase, potassium feldspar, and quartz). Eu(III) heterogeneously adsorbed on biotite, plagioclase, and quartz and homogeneously on potassium feldspar. The histograms of the fluorescence decay rates of adsorbed Eu(III) indicated efficient quenching of Eu(III) fluorescence probably due to Eu(Ill)-surface interaction or the formation polynuclear hydoxo Eu(III) species on the surfaces. It was also revealed that single species of Eu(III) was observed on biotite and two species on plagioclase and potassium feldspar. The adsorption of Eu(III) on the granite surface was highly heterogeneous. The TRLFM measurements of different regions of the granite surface turned into the finding of Eu(III) with different fluorescence decay rates. Comparing with the fluorescence decay histograms of the mineral constituents, Eu(III) clearly adsorbed on the feldspar family. It was also found that Eu(III) adsorbed as an outer-sphere complex and on an altered mineral of the granite.