Thin layer chromatography used for investigations on the Szilard-Chalmers effect

After irradiation with neurons, bariumkryptate nitrate was separated from barium nitrate by thin layer chromatography. The 139Ba activities in the two fractions were measured. After decay, the relative amounts of stable barium were determined by neutron activation analysis. A formula was derived for the calculation of the enrichment factor directly from the four counting rates. The two components mentioned above, one or the other with 131Ba as tracer, were brought into contact with each other for a moment and then separated by chromatography. The exchange rates indicated that the enrichment had been cancelled to a large degree by isotopic exchange. The procedures, recommended as a test for Szilard-Chalmers targets, were checked with cobalt(III) acetylacetonate. (author)