High sensitivity measurement of trace chemical species by selective X-ray excitation
| Project/Area Number |
60470064
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
工業分析化学
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| Research Institution | University of Tokyo |
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Principal Investigator |
GOHSHI Yohichi Univ. of Tokyo; Dept. of Ind. Chem., 工学部, 教授 (90111468)
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| Co-Investigator(Kenkyū-buntansha) |
FUKUSHIMA Sei Univ. of Tokyo; Dept. of Ind. Chem., 工学部, 助手 (70189934)
MIYAMURA Kazuo Univ. of Tokyo; Dept. of Ind. Chem., 工学部, 助手 (40157673)
IIDA Atsuo National Laboratory for High Energy Physics; Photon Factory, 放射光実験施設, 助教授 (10143398)
SAWADA Tsuguo Univ. of Tokyo; Dept. of Ind. Chem., 工学部, 助教授 (90011105)
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| Project Period (FY) |
1985 – 1986
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| Project Status |
Completed (Fiscal Year 1986)
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| Budget Amount *help |
¥5,400,000 (Direct Cost: ¥5,400,000)
Fiscal Year 1986: ¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1985: ¥3,400,000 (Direct Cost: ¥3,400,000)
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| Keywords | Chemical state analysis / X-Ray fluorescence analysis / Synchrotron radiation / Selective excitation / Trace analysis / Iron compounds / X-Rays / 吸収端 |
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| Research Abstract |
The purpose of the present study is to develop a method of chemical state analysis by selective excitation of specific chemical states with monochromatic X-rays. The experiments were performed at the Photon Factory (KEK) using an intense monochromatic X-ray beam supplied from the synchrotron radiation light source at the storage ring of PF. We obtained the following results.
1. Quantitative comparison of the absorption and the fluorescence method
The sleetive excitation of X-ray fluorescence is based on the change in absorption spectra. We performed theoretical analysis of the relation between absorption spectra and fluorescence spectra excited with monochromatic X-rays, and obtained the result that selectively excited X-ray fluorescence spectra and absorption spectra coincided with each other in case of thin or dilute samples. The appropriate range was less than 40 <micro> g/ <cm^2> or 400ppm (Fe in C). We also analyzed quntitatively the change in selectively excited X-ray fluorescence
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spectra caused by the deviation from the thin or dilute condition. The coincidence between absorption and fluorescence spectra was confirmed for 11 iron compounds.
2. Effect of scattering and S/N
In case of a trace measurement, scattering forms background and governs lower detection limit. A method for supression of background was investigated using polarization of SR light source. A procedure of quantitative evaluation of scattering was developed taking into account the polarization characteristics of the SR light source and the characteristics of the monochromator system. The results showed that the effect of multiple scattering was not very large.
3. Chemical state analysis
Quantitative chemical state analysis was performed on the mixture system of <Fe^(2+)> and <Fe^(3+)> giving satisfactory results. Quantitative estimation of lower detection limit was performed under the present PF ring conditions. The estimation showed that 10ppm Fe of iron compounds were detectable with 1min measurement. Less
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Report
(1 results)
Research Products
(7 results)
