Development of a colorimetric test for quantification of uranium in drinking water

A colorimetric method was developed for the determination of uranium in groundwater. The detection limit for the method is approximately 25 μg/L uranium, which is below the maximum contaminant level for uranium in drinking water, 30 μg/L. The method is rapid and requires little technical training to conduct, allowing it to be used by consumers, in the laboratory, or in the field. The two-step technique involves preconcentrating uranium using a U/TEVA-2 extraction chromatographic resin followed by complexation with a pyridylazo indicator dye, 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol. If color change is visible to the eye, the concentration of uranium in groundwater is above the detection limit. Preconcentration using U/TEVA-2 also serves to eliminate metals that may interfere with the quantification of uranium.