Monitoring of Uranium (VI) in Water Samples after Preconcentration with Modified Nanoporous Silica and Color Reaction by Br-PADAP

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Abstract

In this work, a novel method for trace detection of uranium (VI) in water samples is introduced. The method involves two-steps: selective preconcentration of uranium (VI) using amine functionalized nanoporous silica and reaction of uranium (VI) with 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol (Br-PADAP) to reach a colorful complex. The effect of various parameters on preconcentration and formation of uranium (VI) complex were studied and optimized. The effect of some metal ions interferences such as Cu(II), Fe(II), Zn(II), Ni(II), Pb(II), Th(IV) and Cd(II) with the concentrations of 50 ppm reveal that these ions )except for Cu(II)), does not have any interference in this method. The detection limit of the method was obtained as 0.02ppm. This concentration is appropriate for developing the eye sensing technique for trace detection of uranium (VI) ions. The method was successfully applied for trace detection of uranium (VI) in tap, sea and well water samples.

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