SEPARATION OF CARRIER-FREE YTTRIUM-90 FROM STRONTIUM-90 A RADIOCOLLOIDAL METHOD
Sr/sup 90/ and Y/sup 90/ were adsorbed on NH/sub 4/-form Dowex 50-X/sub 4/ (5 100 mesh) columns and the radiocolloidal Y/sup 90/ was eluted with ethanol or methanol. The NH/sub 4/ form was chosen because its basicity facilitates the formation of radiocolloids. Radiocolloids are not adsorbed on the resin whereas the ionic species are readily adsorbed. Max fractions of the radiocolloids (18% with ethanol and 7% with methanol) were eluted by 50% aqueous solutions of the organic solvents. The percentage of Y/sup 90/ removed by ethanol solutions was higher than that by methanol solutions except when the 100% nonaqueous solvents were used. When no activity was present in the effluent solution, the column was scanned with a GM counter. It was observed that, in addition to the intense activity remaining at the top of the resin bed where Sr/sup 90/ solution had been originally adsorbed, there was a wide distribution of activity over the resin bed. This suggested the fractional conversion of the ionic form to colloidal agglomerates and the anomalous adsorption of the latter on the resin, since it seems unlikely that the adsorption of radiocolloids on the resin particles was occurring. The anomalous adsorption was probably due to the formation of colloidal agglomerates which were growing in size and retained in the channels among the resin particles. The effect of adding the alcohols to citric acid solution on the elution of Y/sup 90/ was also studied. When the pH of solutions of citric acid and ethanol in the desired proportions were adjusted to 3.5 by ammonia, all the Y could be eluted, the distribution coefficient increased ( approximates twice as great as in citric acid solutions), and the elution curves were tailed; so that 15 or more column volumes of influent solutions were necessary for the complete elution. Thus the anomalously adsorbed agglomerates can be broken up by passing a complexing reagent such as citric acid of pH 3.5, although the destruction of agglomerates may be time consuming and tailing during elution may result. It seems that a longer column is associated with the effective removal of radiocolloid, but a shorter one provides sharper separation. (BBB)
- Research Organization:
- National Tsing Hua Univ., Hsinchu, Taiwan
- Sponsoring Organization:
- USDOE
- NSA Number:
- NSA-17-035893
- OSTI ID:
- 4665980
- Journal Information:
- J. Chinese Chem. Soc. (Taiwan), Vol. Vol: 7; Other Information: Orig. Receipt Date: 31-DEC-63
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
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