Adsorptive Stripping Voltammetric Determination of Trace Uranium with a Bismuth‐Film Electrode Based on the U(VI)→U(V) Reduction Step of the Uranium‐Cupferron Complex

Abstract

This work reports the use of adsorptive stripping voltammetry (AdSV) for the determination of uranium on a preplated rotating-disk bismuth-film electrode (BiFE). The principle of the method relied on the complexation of U(VI) ions with cupferron and the subsequent adsorptive accumulation of the complex on the surface of the BiFE. The uranium in the accumulated complex was then reduced by means of a cathodic voltammetric scan while the analytically useful U(VI) ! U(V) reduction signal was monitored. The experimental variables as well as potential interferences were investigated and the figures of merit of the method were established. Using the selected conditions, the 3s limit of detection for uranium was 0.1 mg L À1 at a preconcentration time of 480 s and the relative standard deviation was 4.7% at the 5 mg L À1 level for a preconcentration time of 120 s (n ¼ 8). The accuracy of the method was established by analyzing a reference sea water sample.

A Decade with Bismuth‐Based Electrodes in Electroanalysis

“…All significant trends outlined in the previous sections remained in the fore and the newest activities resulted in another remarkable portion of new publications [70 -96]. The individual contributions came from "traditional" propagators of bismuth electrodes from the U.S.A. [71,83], Slovenia [72,85,89], Czech Republic [72,90,96], Poland [78], Greece [72,73,82,87,90], Portugal [75], France [86,92] and the UK [94]; however, the sixth year of contemporary era of electroanalysis with BiEs was also the sign of new research groups appearing over the whole world. Thus, the aboveintroduced "Bismuth Club" -a hypothetical association and so-far unrealized idea of some pioneers in the field -could invite further members from Europe (Germany [70,93], Spain [80], Italy [91], and Serbia [77]), North America (Delaware, USA [76]), and the Far East (China [79,84], Thailand [76]), and Australia [74,81].…”

“…Besides determinations of Cd(II) and Pb(II) [72,81,86,87,88,90,95], of interest were the following ions or other inorganic species: Zn(II) [72,78], Tl(I) [72,96], In(III) [72], Sn(II/IV) [74,89], Cu(II) [81], Fe(II/III) [76,00], Mn(II/IV) [72,76], Co(II) and/or Ni(II) [70,85,92], U(VI/V) [73], and newly also Al(III) [82], V(IV/V) [83], Mo(V/VI) [71], and O 2 , S x 2À , S 2 O 3 2À , I…”

Stripping Voltammetry of Trace Metals at Bismuth‐Film Electrodes by Batch‐Injection Analysis

“…Experiments were carried out using a 40 mg L À1 U(VI) solution in the presence of cupferron and the peak height increased with the preconcentration time up to 60 s; this value was used for further experiments. Again, this behaviour was different from batch experiments using convective stirring in which a constant diffusion layer exists preventing depletion of the analyte species from the vicinity of the electrode and the amount of analyte deposited is solely determined by the establishment of an equilibrium between the analyte concentration in the solution and its surface concentration on the electrode [41]. Figures 5a and b illustrate stripping voltammograms obtained with BIA on a BiFE for the determination of UV(I) and Ni(II) and Co(II), respectively, in the range 10 -70 mg L À1 (calibration curves are shown as insets).…”

The Cyclic Renewable Mercury Film Silver Based Electrode for Determination of Uranium(VI) Traces Using Adsorptive Stripping Voltammetry

“…Only in a few cases other electrodes such as the rotating-disk bismuth-film electrode [26], or the modified carbon paste electrode [27] were used.…”