Radiochemical neutron activation analysis of selenium using carbamate extraction

Studies on the solvent extraction of selenium as its carbamate complex form the basis for the application of this system to separate 75Se from irradiated biological matrices in radiochemical neutron activation analysis of this element. Investigation of several sample destruction techniques leads to preferred techniques of oxygen flask combustion for dry materials or acid wet-ashing with nitric and sulphuric acids plus hydrogen peroxide for fresh material. In both cases selenium(IV) was extracted with a toluene solution of carbamate and after γ-counting, the chemical yield was then determined by re-activation of sup(81m)Se. The results were verified by analyses of various SRMs. (author)