1996 Fiscal Year Final Research Report Summary
FUNDAMENTAL STUDIES ON APPLICATION OF ANION CARRIERS TO SEPARATION AND ANALYSIS OF ANIONS BY MEANS OF LIQUID-LIQUID PARTITION
| Project/Area Number |
07650979
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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 | KUMAMOTO UNIVERSITY |
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Principal Investigator |
JYO Akinori KUMAMOTO UNIVERSITY,DEPARTMENT OF APPLIED CHEMISTRY AND BIOCHEMISTRY,PROFESSOR, 工学部, 教授 (40038047)
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| Project Period (FY) |
1995 – 1996
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| Keywords | Solvent extraction / Ion-pair extraction / Anion carrier / Metalloporphyrins / Inorganic anions / Fluoride ion / Nitrite |
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| Research Abstract |
In order to clarify the anion selectivity of metalloporphyrin anion carriers in liquid-liquid partition systems, extraction of anions with Mn (III), Mo (V), Fe (III), Co (III) and In (III) complexes of tetraphenylporphyrin (TPP) was examined ; hereafter, respective complex cations are denoted as Mn (TPP)^+, MoO (TPP)^+, Fe (TPP)^+, Co (TPP)^+, and In (TPP)^+. The following results were obtained.
i) In the case of MoO (TPP)^+, Fe (TPP)^+, and Co (TPP)^+, hydrolysis of the complex markedly occurs across the organic and aqueous phases, but not so markedly in the case of Mn (TPP)^+ and In (TPP)^+. Then, solvent extraction anion exchange constants can be successfully determined for Mn (TPP)^+ and In (TPP)^+ toward 5 kinds of anions in water-chloroform and water-1,2-dichloroethane systems. For MoO (TPP)^+, Fe(TPP) ^+ and Co (TPP)^+, their anion selectivity was evaluated semiquantitatively by measuring anion exchange under acidic conditions to depress the unfavorable effect of hydrolysis. The results obtained clearly imply that the anionselectivity is strongly affected not only by central metal species but also by organic solvent species.
ii) In order to clarify the mechanism of anti-Hofmeister anion selectivity of metalloporphyrins, conductivities of various monovalent anion salts of MoO (TPP)^+, Mn (TPP)^+, and In (TPP)^+ in 1,2-dichloroethane were measured. The results lead to the conclusion that overall-anion selectivity of metalloporphyrin anion carriers is governed by the free energy change in binding of anions with the carriers in organic phases and that of transfer of anions form water to the organic phases.
iii) Based on the results mentioned above, highly selective solvent extraction spectrophotometric determination of fluoride was developed. The proposed method can selectively determine the fluoride of sub-ppm levels. Even in the presence of chloride, sulfate, and nitrate in large excess (100-folds of fluoride), the recovery of fluoride was nearly equal to 100 %.
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