Electrochemical Determination of Low Levels of Uranyl by a Vibrating Gold Microelectrode.

Citation:

Y. Peled, Krent, E. , Tal, N. , Tobias, H. , and Mandler, D. 2015. “Electrochemical Determination Of Low Levels Of Uranyl By A Vibrating Gold Microelectrode.”. Anal. Chem. (Washington, Dc, U. S.)Analytical Chemistry (Washington, Dc, United States), 87, Pp. 768 - 776.

Abstract:

The authors report the sensitive electroanal. detection of uranium(VI) in aq. solns. Uranium commonly exists in aq. solns. as its oxo ion, uranyl (UVIO22+). The detection of uranyl was accomplished by the authors through its deposition upon redn. by two electrons to the insol. UO2 using a bare disk gold macroelectrode and anodic stripping voltammetry (ASV). This gave an unsatisfactory detection limit of \~1 × 10-5 M uranyl. Also, the evolution of hydrogen bubbles blocked the electrode surface as a result of water redn. at neg. deposition potential (-0.7 V vs. Ag/AgCl). The application of a 25 μm diam. Au microwire electrode on which UO2 pptd. at neg. potential (-1.2 V) improved substantially the detection limit. Further improvement was accomplished by vibrating the microwire working electrode, which increased the amts. of UO2 deposition due to decreasing the diffusion layer. The effect of the vibrating amplitude and frequency on the electroanal. response was studied and optimized. Eventually, a detection limit of \~1 × 10-9 M uranyl was achieved using a 5 min deposition time, -1.2 V deposition potential, and vibrating the electrode at frequency of 250 Hz and amplitude of 6 V. [on SciFinder(R)]