Determination of Uranium in Natural Waters by Solid Phase Spectrometry

Abstract
A microdetermination method (at the μg1−1 level) for uranium has been developed, based on Solid-Phase Spectrophotometry (SPS). The uranium reacts with pyridylazo-resorcinol in the presence of fluoride to form a 1:1:1 red ternary complex, which is fixed on an anion-exchange resin. The resin absorbance is measured directly, and allows the determination of uranium in the range of 1–10μg1−1, with an RSD of 4%. The method has been applied to the determination of U(VI) in natural waters from wells located near the deposits of industrial wastes from a uranium mineral plant in Andujar (Spain).