Surfactant Enhanced-Spectrophotometric Determination of Uranium (VI) at Trace Levels by Using Eriochrome Black T as a Chelating Agent

Abstract

92440.60 L mol -1 cm -1 and Sandell's sensitivity of 2.92 µg cm 2-in micellar medium while it allows the determination of uranium in the concentration range of 0.25-2.5 µg mL -1 with a molar absorption coefficient of 57019.44 L mol -1 cm -1 and Sandell's sensitivity of 4.74 µg cm 2-at 565 nm in water. The method has a detection limit of 4.60 µg L -1 (C DL : 3S b /m) at an analytical measurement wavelength of 637 nm with a bathochromic shift of 72 nm. The selectivity of chelating reagent was improved by the use of a mixture containing ethylenediaminetetraacetic acid (EDTA), sulfosalycylic acid and NaF as masking agent . The proposed method has been successfully applied to the determination of uranium at trace levels in different environmental water samples such as tap-water, natural springwater and river-water. The precision (with coefficient of variation of 1.85%) and the accuracy obtained were highly satisfactory. In order to test the accuracy and validation of the method, the certified reference material (TMDA-70; fortified lake water sample) was also analyzed. It was found that the found and the certified values were in good agreement for validating the surfactant enhanced-spectrophotometric method.