Neutron activation analysis of elements extracted into organic media

It is sometimes worthwhile, especially in solvent extraction studies by radiochemical techniques, to neutron irradiate the organic phase after extraction and directly count the same. Problems arise in comparing gamma activities in the corresponding aqueous phases, eventually irradiated after extraction, and in aqueous standards. Many factors may affect, though in a different way, both the neutron activation and counting steps: the former being a function of neutron absorption in the organic medium that may be especially relevant in the case of chlorine containing solvents and of the different neutron thermalizing properties of the same. To test these effects, tributyl phosphate in various diluents was used as an extractant for the chlorocomplexes of some noble metals, namely Pd, Pt, Ir, Os and Au. The effect of different thermalizing power of the media by comparing the activities of irradiated aqueous and organic samples containing same amounts of neutron absorbing elements was also evaluated