|Title:||序列萃取方法劃分土壤鎵與銦物種的適用性之探討||Other Titles:||Evaluation of Sequential Extraction for Speciation of Gallium and Indium in Soil||Authors:||蘇子珊
|Keywords:||鎵;銦;序列萃取;物種劃分;gallium;indium;sequential extraction;Chemical fractionation||Issue Date:||Jan-2020||Publisher:||國立臺灣大學||Start page/Pages:||1-91||Source:||臺灣大學農業化學研究所學位論文||Abstract:||
Gallium(Ga) and indium(In) are widely used in high-tech industries, which resulted in their release into the environment and the increased risks of exposure to public health. The impact of soil metal pollution on ecological and public healths depends on the abundance and distribution of metal pollutants in various chemical phases. Given that, sequential extraction methods have been developed to determine metal fractionation to provide information about the availability and mobility of metal pollutants in soil. However, a sequential extraction method is often not applicable to all metal pollutants. Therefore, different methods have been developed and evaluated, and Tessier and BCR method are the most widely used ones so far. For Ga and In, it is unknown whether the sequential extraction methods are suitable for the fractionation of Ga and In in soil. Therefore, the purpose of this study is to assess the applicability of the Tessier and BCR sequential extraction method to the fractionation of Ga and In in soil. Illite, calcite, birnessite, ferrihydrite, goethite and humic acid with known Ga and In concentrations were prepared and extracted with each reagent to confirm the specificity of the reagent in extracting Ga and In, After single extraction, sequential extraction methods were conducted for those materials to determine the correlation and consistency between the predicted value and the actual value. Finally, three soils spiked with Ga or In were used for sequential extraction experiments to evaluate the analytical performance of the extraction method through the comparison with the corresponding XAS speciation results. The experimental results show that the fractionation results of calcite, illite, and humic acid with a single reagent in the two sequential extraction methods are not as expected; Tessier method has a better extraction effect on goethite, and BCR method cannot extract the target elements in goethite. Birnessite and ferrihydrite have good extraction effects in the two methods. The sequential extraction results of Ga-bearing or In-bearing materials show that Tessier method is more suitable for all Ga-bearing minerals and humic acid than BCR method. Tessier method is suitable for In-bearing minerals and humic acid except for calcite, and BCR method is also suitable for illite, birnessite and ferrihydrite. For the soil, the Tessier method is more suitable for In-bearing minerals and humic acid than BCR method. The sequential extraction results of Ga- or In-spiked soil show that both Tessier method and BCR method are suitable for evaluating the availability of Ga and In in soil.
|Appears in Collections:||農業化學組|
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