THERMAL NEUTRON ACTIVATION ANALYSIS OF TANTALUM IN SEA WATER

A thermal neutron activation method was worked out for the determination of traces of tantalum in sea water. Before irradiation tantalum was collected into iron hydroxide from 510 l of sea water sample with a satisfactory recovery. Air dried hydroxide was then irradiated along with a reference standard for a period of up to twelve days at the neutron fluxes of 3·1011n·cm-2·sec-1. Solvent extraction separation using hydrofluoric acid-sulfuric acid-isopropylacetone system gave 182Ta (111 d) in a radiochemically pure form. Activity measurements were taken on a β-proportional counter. As little as 0.1 μg of tantalum in a 5 l of water sample can be determined this way.A detailed description was given for the solvent extraction separation of tantalum. Average tantalum content of sea water was estimated to be 0.00≤0.02 μg/l.