2007 Fiscal Year Final Research Report Summary
Substoichiometric NMR Analysis for Oxygen-containing Organic Compounds
| Project/Area Number |
18550066
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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 |
Analytical chemistry
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| Research Institution | Kanazawa University |
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Principal Investigator |
IMURA Hisanori Kanazawa University, Graduate School of Natural Science and Technology, Professor (60142923)
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| Co-Investigator(Kenkyū-buntansha) |
OHASHI Kousaburo Ibaraki University, College of Science, Professor (60007763)
OHASHI Akira Ibaraki University, College of Science, Lecturer (50344833)
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| Project Period (FY) |
2006 – 2007
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| Keywords | absolute determination / substoichiometry / extraction equilibrium / NMR / oxygen-containing organic compound / Ianthanide complex |
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| Research Abstract |
A novel analytical method of substoichiometric nuclear magnetic resonance analysis (SNMR) for oxygen-containing organic compounds (000 has been proposed The present method is based on the adduct formation of a paramagnetic lanthanide (III) (Ln) chelate as a shift reagent with OOC. The stoichiometry and the equilibrium of the adduct formation of tris(hexafluoroacetylacetonato)-europium(III)(Eu(hfa)_3) or -praseodymium(III) (Pr(hfa)_3) with OOC such as di(2-ethylhexyl) phthalate (DEHP), dimethyl sufoxide (DMSO), poly(ethylene glycol 400) dimethyl ether (PEG), and polyoxyethylene(10) octylphenyl ether (TX100) were studied by the solvent extraction method. The composition of the adducts of Ln(hfa)_3 was found to be only 1:1 for PEG and 1:1 and 1:2 for DEHP, DMSO, and TX100, and the respective adduct formation constants were determined. From the equilibrium analysis by 'H NMR, the adduct formation constant and the chemical shift of OOC protons in the adduct were obtained. This knowledge led to develop SNMR for OOC. The validity of SNMR was demonstrated by the determination of DMSO in a synthetic solution. A substoichiometric amount of Eu(hfa)_3 was added to the sample solution of DMSO and the chemical shift of the methyl-protons was measured by NMR. After a known amount of DMSO was spiked to the sample solution, the chemical shift was measured, and then the amount of DMSO in the sample was calculated. The mM level of DMSO could be determined by only measuring the chemical shift for the analyte without any calibration curves. The repeatability of the chemical shift measurement was as good as 0.01% as relative standard deviation, and the precision and accuracy for the determined values were very high.
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