Masami Izawa
National Institute of Radiological Sciences
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Featured researches published by Masami Izawa.
Journal of Nuclear Science and Technology | 1967
Kazuo Watari; Kiyoko Imai; Masami Izawa
The adsorption and desorption of 137Cs on copper ferrocyanide-anion exchange resin, prepared in the manner previously reported in this Journal in a Short Note, are presented in detail. This resin can also be used for the concentration of the 137Cs found in sea water. The nuclide is adsorbed effectively on the resin from water, hydrochloric acid below 4 M, and on nitric acid below 1M. After adsorpsion on the resin, 137Cs is eluted easily with either nitric acid (>6M), ammonium water, or silver nitrate solution. Adsorption on the resin is specific for 137Cs, and the action is due entirely to the ferrocyanide moiety of the resin. This method is more efficient than the co-precipitation method with copper ferrocyanide for the concentration of radiocesium from a large volume of sea water.
Journal of Nuclear Science and Technology | 1968
Kazuo Watari; Kiyoko Imai; Masami Izawa
Preparation of iron ferrocyanide-anion exchange resin and adsorption of 137Cs on the resin are described. The resin was found to effectively adsorb 137Cs from concentrated nitric acid solution, contrast to the negative results previously obtained with copper ferrocyanide-anion exchange resin. A discussion is given of the possibility of applying the iron resin to the removal of 137Cs from fuel reprocessing waste solution. Fission products were effectively separated from each other with a column of this resin, utilizing the properties possessed by it of both iron ferrocyanide and the parent ion exchange resin.
Journal of Nuclear Science and Technology | 1969
Kazuo Watari; Kiyoko Imai; Masami Izawa
This report discusses the preparation of a number of metal salt-ion exchange resins and their application to radiochemical separation. The resins prepared by the subject method have properties of both metal salt and ion exchange resin. The present report describes the preparation and application of multi-loaded metal salt-ion exchange resin which contain one or more kinds of insoluble metal salt in an ion exchange resin, for which the residual ion exchange ability of an intermediate metal salt-ion exchange resin is utilized. The properties of multi-loaded nickel ferrocyanide-anion exchange resin and nickel ferrocyanide-calcium phosphate-anion exchange resin are also discussed.
Journal of Chromatography A | 1968
Shoichi Kawamura; T. Fujimoto; Masami Izawa
Abstract The RF values of inorganic ions on paper pre-treated with 0.25–2.0 % cellulose acetate and impregnated with various concentrations of 2-thenoyltrifluoroacetone (TTA) was studied by using acetate buffer as a developing agent. 1% cellulose acetate pre-treated paper impregnated with o.2 M TTA was found suitable for reversed phase paper chromatography. The RF values of inorganic ions were examined on the impregnated paper by using various pHs of the developing agent (0.1 M acetate buffer). Separations of PbCu, CoCu, ZnCu and FeCoNi were performed in this system.
Proceedings of the First International Congress of Radiation Protection | 1968
Masami Izawa; Kazuo Watari
Abstract A series of a new type of adsorbents for radionuclides in aqueous solutions has been synthesized consisting of an ion exchange resin and an inorganic salt, and their properties were studied. We named them “metal salt-ion exchange resins”. Preparation of the “resins” are simple and easy. For example, “ferric hydroxide-cation exchange resin” can be made by putting a ferric form of a cation resin into a concentrated hydroxide ion solution, and “copper ferrocyanide-anion exchange resin” by putting a ferrocyanide form of an anion resin into a cupric ion solution. The prepared “resins” have combined adsorption properties of both the metal salt and the exchange resin moieties. They are generally non-hygroscopic and granular, so that they can be stored in dry state. In principle, the “resins” can be made by any combination of insoluble metal salts and ion exchange resins. By considering adsorption capacity and exchangeability of metal salts and resins, a wide variety of applications of the “resins” can be made for chemical and radiochemical analyses; e.g. “metal hydroxide-resins” for adsorption of zirconium, ruthenium and alkaline earth ions, “metal ferrocyanide-resins” for specific adsorption of cesium and for mutual separation of alkali metals and of fission products (Sr, Zr, Nb, Ru, Cs, Ce). A few examples of applications of “ferrocyanide-resins” are presented.
Journal of Radioanalytical and Nuclear Chemistry | 1977
Kiyoko Imai; Kazuo Watari; Masami Izawa
Recently, a new type of resinous adsorbent has been developed as an effective adsorbent for a number of organic materials. The adsorbent has macro-reticular structure and no ion-exchange capacity.This paper deals with the adsorption of typical fission products and induced radionuclides on Amberlite XAD-2, with 8-hydroxyquinoline (oxine) as the organic reagent.It was found that60Co,59Fe,144Ce,95Zr, and106Ru were transferred to the adsorbent phase from various solutions, when oxinates of the nuclides were formed in the solutions. Without oxine, most of the nuclides were not adsorbed on the adsorbent.137Cs and85Sr were not adsorbed on XAD-2 with or without oxine.
Bunseki Kagaku | 1961
Masami Izawa; Hiroyuki Tsubota; Atsushi Kasai
セロソルブによるカルシウムとストロンチウムとの分離法を検討し,特にブチルセロソルブが有用であることを示した.ブチルセロソルブは沸点が高いので脱水精製が容易であり,またカルシウムおよびストロンチウムの硝酸塩をあらかじめ無水塩にする必要はなく,加熱沸騰で脱水が完全である.その方法をさらに拡張して水溶液にブチルセロソルブを加えて,加熱脱水してストロンチウムを析出させる方法も検討した.本法をフォールアウトなどのなかの90Srの分析に適用するときには,常法によりアルカリ土類元素のみを取り出したのち,その相互分離に本法を適用すればよい.これらのことから,ブチルセロソルブによるカルシウムとストロンチウムとの分離法は従来用いられてきた発煙硝酸法にかなりの部分に置きかえうる方法であることがわかった.
Bulletin of the Chemical Society of Japan | 1969
Shoichi Kawamura; Katsumi Kurotaki; Masami Izawa
Journal of Nuclear Science and Technology | 1965
Kazuo Watari; Masami Izawa
Journal of Nuclear Science and Technology | 1967
Kazuo Watari; Kiyoko Imai; Masami Izawa