| 摘要 |
1,231,159. Radio-active isotopes. UNION CARBIDE CORP. 14 Aug., 1969 [28 Aug., 1968], No. 40679/69. Heading G6R. Radio-active Ba-137 m. is prepared by elution of Cs-137 on a substrate of a cobalt ferrocyanide of the formula M 2 [CoFe(CN) 6 ], where M is Ni, Zn, Fe(II), or Cu(II). To avoid breakthrough of Cs-137, the substrate may be heated for a short period before elution. A reducing agent, e.g. graphite, carbon black, or charcoal, may be mixed with the cobalt ferrocyanide in order to maintain a high rate of Ba-137m recovery. An anion exchanger such as hydrous zirconium oxide coated with cupric ferrocyanide may be used to remove Cs-137 from the eluent. The eluent may be water or dilute hydrochloric or nitric acid; for preparing a sterile solution for medical research or diagnosis, an isotonic saline solution is used. A statement of prior art refers to substrates consisting of zirconium phosphate, ammonium phosphomolybdate and asbestos, and cupric ferrocyanide.
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