Determination of uranium in water samples by ICP-AES with chelating resin disk preconcentration

An analytical method of uranium in water samples by ICP-AES using a 3M Empore chelating resin disk for solid-phase extraction has been developed. A trace amount of uranium was quantitatively collected with an Empore chelating resin disk (47 mmφ) at a flow rate of 100 - 150 ml min-1 from a sample solution (pH 5.0) under the presence of 100 mM CH3COONH4 and 1 mM DCTA. The interference elements (Fe, Th, etc) were separated at the same time during the preconcentration of uranium. Uranium was then quantitatively eluted with 7.5 ml of 2 M HNO3. A preconcentration factor of 200-fold was achieved with a 2.0 l sample. The present method has been applied to the determination of uranium in seawater and mineral-water samples. The analytical results of uranium were almost in good agreement with literature values and the results of other methods (ICP-MS and α-ray spectrometry). The concentrations of uranium in mineral-water samples were from < 0.1 to 1.7 μg l-1. (author)