2002 Fiscal Year Final Research Report Summary
Development of Electrothermal Vaporization/ICP-MS for Microtrace Analysis
| Project/Area Number |
13650868
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
工業分析化学
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| Research Institution | Nagoya University |
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Principal Investigator |
TANAKA Tomokazu Nagoya University, Graduate School of Engineering, Research Associate, 工学研究科, 助手 (40236609)
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| Project Period (FY) |
2001 – 2002
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| Keywords | ICP-MS / Electrothermal vaporization / Microsample / Biological sample / Selenium / Arsenic / High-purity metal / Coprecipitation |
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| Research Abstract |
A detachable sample-injector with a coiled tungsten filament was constructed for the effective introduction of tiny amounts of sample into ICP-MS. A 5 μl volume of the sample was placed on a filament and an injector was inserted into a plasma torch. After desolvating the sample, the filament was electrically heated. The resulting vapor was transferred to the plasma for the determination of As and Se. The signal intensities increased by almost 100 times as compared with the values in a previous study, where a looped tungsten filament was heated outside the plasma torch. The absolute detection limits were 0.5 pg for As and 1.1 pg for Se.
The proposed method was applied to the determination of As and Se in certified reference human hair (5 mg). The analytical results were 0.29±0.03 μg g^1 for As and 1.8±0.2 μg g^1 for Se, which are in good agreement with the certified values (As 0.31±0.02 μg/g, Se 2.0±0.08 μg/g). The analysis was tried with 0.50-mg weight of the sample. The sample was deco
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mposed with 10 μl of 14 mol/l HNO_3 and 2 μl of 30% H_2O_2 in a PTFE high-pressure decomposition vessel. The resulting solution was mixed with 25 μl of 1 μmol/l KMnO_4 solution and evaporated to dryness. The residue was dissolved in 500 μl of 1 mol/l HNO_3. The addition of KMnO_4 to the sample was essential for the prevention of serious losses (30〜50%) of analytes during evaporation. The results (0.30±0.01 μg/g for As and 2.0 ± 0.2 μg/g for Se) agreed closely with the certified values.
The proposed method was also applied to the determination of Se in high-purity copper (99.9999%). After the acid decomposition of a sample (200 mg), a 5 μl portion of the resulting solution was directly placed on a filament and the signal intensities of ^<82>Se+ were measured. Copper matrix, however, significantly decreased the signals and immediately deteriorated filaments. Copper in the sample solution was effectively removed by coprecipitation with iron hydroxide, and consequently, μg/g level of Se in the sample was successfully determined. Less
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Research Products
(6 results)
