Project/Area Number |
03650610
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Research Category |
Grant-in-Aid for General Scientific Research (C)
|
Allocation Type | Single-year Grants |
Research Field |
工業分析化学
|
Research Institution | Science University of Tokyo |
Principal Investigator |
TANAKA Tatsuhiko Science University of Tokyo, Faculty of Engineering, Assistant professor, 工学部第1部, 講師 (40084389)
|
Project Period (FY) |
1991 – 1992
|
Project Status |
Completed (Fiscal Year 1992)
|
Budget Amount *help |
¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 1992: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1991: ¥1,100,000 (Direct Cost: ¥1,100,000)
|
Keywords | High-purity metal / Trace analysis / Purity test / Microscale preconcentration / Cathodic stripping voltammetry / Coulometric titration / High-purity steel / 微量不純物 / マイクロスケ-ル予備濃縮 |
Research Abstract |
The present report describes the appropriate methods for the purity tests of high-purity metals for creating new functional materials. 1. Determination of trace impurities at the low ppm level in high-purity metals frequently requires preconcentration steps to improve detection limits, precision and accuracy. Microscale preconcentration techniques developed are useful for the analyses of expensive and precious samples available only in small quantities and studies of heterogeneous distribution of trace elements in high-purity metals. Microscale preconcentration techniques using 1- to 10-milligram samples and microliter volumes of solutions seem to be desirable from viewpoints of economy of high-purity reagents as well as minimization of experimental wastes. In addition, they require a narrower working bench space and sometimes are more rapid than conventional ones. Several simple apparatus and new techniques for ion exchange, liquid-liquid extraction and electrolytic separations have be
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en devised to attain easy and secure operations and ensure the precision and accuracy of analytical results. 2. Cathodic stripping voltammetry (CSV) is a highly sensitive analytical technique that combines a preconcentration step (pre-electrolysis) with a determination step (stripping). Some discrepancies between the experimental results of CSV were clarified and reliable practical methods were established for the determination of sulfur and manganese in high-purity metals. 3. Coulometric titration is one of the most precise and accurate techniques of chemical analysis and makes calibrations unnecessary. A few useful methods were proposed for directly purity tests of high-purity metals. 4. New, simple and rapid methods were developed for the determination of trace non-metal elements in high-purity steels. Carbon, sulfur and phosphorus in steels were determined in safety and with good precision and accuracy by a modified wet chemical oxidation-nonaqueous coulometric titration, CSV with a silver disk electrode after conversion of sulfur into hydrogen sulfide and reflectance photometry with a hydrogen sulfide of phosphine detecting tape, respectively. Less
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