2003 Fiscal Year Final Research Report Summary
Preparation of Chelating Adsorbent for Differentiation of Oxidation States and Its Application to Speciation of Toxic Metals
| Project/Area Number |
13440218
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
分離・精製・検出法
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| Research Institution | Chiba University |
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Principal Investigator |
OGUMA Koichi Chiba University, Engineering, Professor, 工学部, 教授 (60009529)
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| Project Period (FY) |
2001 – 2003
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| Keywords | Chelating adsorbent / Speciation / Selen / Flow Injection Analysis / Environmental Analysis |
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| Research Abstract |
It is important to differentiate the chemical species of varying oxidation states of toxic elements from each other because the biological effects of elements strongly depend on their oxidation states.
In this work, a flow injection analysis system was established for the determination of selenium (IV) and (VI) and applied to the speciation of selenium in ground water. The analysis system involved a Bismuthiol II loaded anion-exchange resin mini-column to separate selenium (IV) and (VI) and a detection system for selenium (IV). Selenium (IV) was detected by its catalytic action to the reduction of methylene blue by sulfide.
The flow injection analysis system was constructed with PTFE tubing of 0.5 mm inner diameter and Daiflon connectors. Sample solution was injected into a carrier solution (0.1 M HCl) and selenium (IV) was selectively adsorbed on the Bismuthiol II loaded resin to be separated from other species. Selenium (IV) adsorbed on the column was eluted by penicillamine-hydrochloric acid and mixed with sulfite-sulfide and methylene blue solutions, followed by the measurement of the decreasing absorbance of methylene blue at 665 nm. The total concentration of selenium (IV) and (VI) was measured by injecting the sample solution boiled with hydrochloric acid to reduce selenium (VI) to selenium (IV).
The sample throughput is about 12 and the relative standard deviation is less than 2% when 0.5μg Se(IV)/ml was measured four times. If 20ml of sample solution is injected into the analysis system, 5ng Se/l can be measured.
The proposed analysis system was successfully applied to the speciation of selenium in ground water.
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