Determination of Uranium in Aqueous Solutions by Means of Gamma Absorptiometry

Abstract

A method was developed for the determination of uranium in aqueous solutions acidified with nitric acid which were of various densities and had various contents of aluminum nitrate. The method is based on the principle of gamma absorptiometry using two monoenergetic gamma radiations whose energies include the K absorption edge of uranium. Two measurements rnust be carried out for each of the two gamma energies, i.e., first the measurement of the intensity of the penetrating radiation for the cell filled with water and, secondly, the measurement of the intensity of the penetrating radiation for the cell filled with the simple solution. Moreover, the k-factor for the arrangement used must be determined in advance by means of a correction standard. These measurements and the data from the calibration curve can then be used to determine the uranium concentrations in the simple solutions. Matrix effects play no role under the conditions of measurement applied. The method was studied for solutions with uranium concentrations in the range of 1-20 g of uranium/l, the concentration of nitric acid and of aluminum nitrate being varied. In the range of concentrations investigated. the relative standard deviation of an individual measurement was 0.71%.