1996 Fiscal Year Final Research Report Summary
Development of highly sensitive method for the determination of trace
| Project/Area Number |
07555259
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Section | 試験 |
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| Research Field |
工業分析化学
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| Research Institution | Tohoku University |
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Principal Investigator |
KANEKO Emiko Tohoku Univ., Fac. of Engineering, Associate Researcher, 工学部, 助手 (00241539)
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| Co-Investigator(Kenkyū-buntansha) |
SOURIN Takaaki Mitsubishi Kasei Corporation, Research Center, Chief researcher, 横浜総合研究所, 主任研究員
YOTSUYANAGI Takao Tohoku Univ., Fac. of Engineering.Professor, 工学部, 教授 (00001199)
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| Project Period (FY) |
1995 – 1996
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| Keywords | Autocatalytic reaction / Kinetic analysis / Constant sensitivity detection system / Ultratrace cobalt (II) ion / Flow injection analysis / Spectrophotometric determination / Reaction mechanism |
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| Research Abstract |
Autocatalytic reactions, in which the reaction product acts as a catalyst, are one of the most effective amplification systems for detection of ultra-trace chemical species. Mathematical model calculation shows that the autocatalytic systems provide the same sigmoidal reactant concentration-time profile at the inflection time for any initial concentration of catalyst, that is, only inflection time correlate with it. We found that it should be great value as a kinetic constant sensitivity detection system and theoretically infinite sensitivity detection methods for catalysts.
It was one model for realizing the autocatalytic reaction in laboratory system that the decompmsition of the metal complex causes an amplification of the metal ion having catalytic effect on the own complex. Based on some knowledges about metal complexes got from new analytical method, which is developed in our laboratory and named "kinetic differentiation mode high Performance liquid chromatography (KD-HPLC)" , we have found the decomposition of the inert Co (III) -pyridylazo dye complexes with peroxomonosulfate acts as an excellent indicator reaction system for cobalt (II) ion in phosphate buffer media. The determination limit of cobalt (II) ion was 10^<-10> mol dm^<-3>. Furthermore 10^<-6>-10^<-3> mol dm^<-3> of inhibitors, carboxylic acids and bromide ion, could also be determined kinetically. Theoretically, this system has potential applicability to substances that may act as triggers of the reaction.
Kinetic analysis data for spectrophotometry, stopped-flow method, and radical scavenger addition experiment have given some informations on the reaction mechanism. For instance, the decomposition reactions of ligand and complex are both parallel one with metal-catalysis and non-catalysis, however, they advance via different reaction paths. These results are important knowledges to construct an ideal autocatalytic reaction system.
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