Kinuyo Ogura

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The mechanism of ion-exchange of cobalt(II) and nickel(II) on a resin loaded with 5-sulpho-8-quinolinol has been studied, and the chelate-forming reaction in the resin matrix shown to be rate-determining. The observed rate seems to be related to the rate of water-exchange with the metal ion in the aqueous phase, suggesting that complexation in the resin(More)
A chelating agent-loaded resin consisting of 8-quinolinol-5-sulfonic acid and an anion-exchange resin (HOx-resin) was prepared in order to concentrate trace chalcophile elements in natural water samples selectively before neutron activation analysis. The exchange capacity of the Diaion SA No. 100 for the reagent (1.8 meq . g-1 resin) corresponds(More)
A substoichiometric method for the determination of zinc has been developed. Zinc can be separated from other cations by using an anion-exchanger loaded with a substoichiometric amount of 8-quinolinol-5-sulphonic acid. Interfering metals can be removed beforehand by dithizone extraction. The feasibility of this method for water analysis was also examined.
A combined method of dithizone-extraction and carbon powder column adsorption was applied to concentrate trace amounts of copper (II) and mercury (II) in natural water samples before neutron activation analysis. The sample solution was adjusted to pH 1.0 with nitric acid, an aliquot of which as taken in a 500 cm3 separating funnel and then 5.0 cm3 of 0.01%(More)
The ion-association equilibrium of the dipicrylaminate ion (DPA(-)) was investigated in an aqueous solution with alkali metal ions and with its 18-crown-6 ether complexes as pairing cations by capillary zone electrophoresis (CZE). Although DPA(-) is precipitable with the pairing cations of K(+) and Cs(+) in a homogenous aqueous solution, a low concentration(More)
The entropy changes of Ca(2+)-, Mn(2+)-, Ni(2+)- and Pb(2+)-EDTA complex-formation reactions were measured at various pH-values. The entropy changes for the Ca, Mn and Pb complexes were practically independent of pH, but that of the Ni complex decreased considerably with pH. It is suggested that mixed-ligand (EDTA, water) complexes of Ni are formed at low(More)
A chelating agent-loaded resin consisting of an anion exchange resin (Dowex 1 X-4) and bathocuproine disulfonic acid (BCS-resin) was prepared. The adsorption behavior of some chalcophile elements as a function of pH by the column method was studied, and mercury was shown to be adsorbed selectively to the BCS-resin at the pH region of 0.5 approximately 1.0,(More)
A chelating agent-loaded resin consisting of an anion exchange resin and zincon which has widely been employed as a specific reagent for zinc(II) and copper(II) in spectrophotometry was prepared. The adsorption behavior of some chalcophile elements was studied in detail, with respect to pH, flow rate and exchange capacity. From the results, it was confirmed(More)
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