Simultaneous quantification of Bi(III) and U(VI) in environmental water samples with a complicated matrix containing organic compounds

Abstract

Trace amounts of bismuth(III) and uranium(VI) can be simultaneously determined in a single scan by adsorptive cathodic stripping voltammetry in the presence of cupferron as a complexing agent. Optimal conditions were found to be: 0.1 mol L−1 acetate buffer (pH 5.3), 5 × 10−5 mol L−1 cupferron, accumulation potential of −0.25 V, and accumulation time of 30 s. The linear range of Bi(III) and U(VI) was observed over the concentration range from 2 × 10−9 to 2 × 10−7 mol L−1 and from 1 × 10−8 to 5 × 10−7 mol L−1, respectively. The influence of the main components of real water samples such as foreign ions and organic substances (surface active substances, humic substances) was precisely investigated. The method was applied to the simultaneous measurements of bismuth and uranium in natural water samples.

Adsorptive Cathodic Stripping Voltammetric Determination of Uranium(VI) in Presence of N‐Phenylanthranilic Acid

“…Table 1 presents some of these methods with potential interferences having a tolerance ratio of≤10 (w/w). The electrodes based on mordant Blue 9 32, 3‐ N ‐benzoyl‐ N ‐phenyl hydroxylamine 28, aluminon 33, cupferron 25–28, L ‐3‐(3,4‐dihydroxyphenyl)alanine (LDOPA) 29,30, catechol 31, propyl gallate 28, 4‐(2‐hydroxyethyl)‐1‐piprazineethane sulfonic acid 46, and oxine 28 suffer from severe interferences by several metal ions. Although, the interference from several elements, when present at concentrations higher than their tolerance level, can be eliminated by adding complexing agents such as EDTA for Cu(II), Cd(II), Pb(II), and Zn(II), or precipitating with urea for Al(III), Th(IV), Bi(III), Fe(III), and Sn(IV) 24,28,30,31,37.…”

“…Therefore, a variety of analytical methods have been used for the determination of uranium, including: radioanalytical methods such as neutron activation analysis (NAA), gamma and alpha spectrometry 10–12; spectrometric methods including spectrophotometry 13,14, spectrofluorimetry 15, inductively coupled plasma (ICP) atomic emission 16, ICP‐mass spectrometry 17, X‐ray fluorescence spectroscopy (XRF) 18; gas chromatography 19; electroanalytical methods including pulse polarography with modified electrodes 20, potentiometry based on ion‐selective electrodes 21 and adsorptive cathodic stripping voltammetry (ACSV) 22–25. Some of these methods suffer from the drawback of complicated and expensive instrumentation which is not available in all laboratories, and/or the requirement for a tedious and time consuming preconcentration step (via extraction or adsorption).…”

“…A number of complexing agents have been suggested for determination of uranium by ACSV including cupferron ( N ‐nitrosophenylhydroxylamine) 22–28, L ‐3‐(3,4‐dihydroxyphenyl)alanine 29,30, catechol 31, mordant blue 9 32, aluminon 33, dipicolinic acid (2,6‐pyridinedicarboxylic acid) 34, chloranilic acid (2,5‐dichloro‐3,6‐dihydroxy‐l,4‐benzoquinone) 35–38, propyl gallate 28,39, diethylenetriaminepentaacetic acid (DTPA) 39, xylidyl blue‐1 40, potassium hydrogen phatalate 41, Schiff base N,N’‐ethylenebis(salicylidenimine) in aqueous 4‐(2‐hydroxyethyl)‐1‐piperazineethanesulfonic acid medium 42, benzene‐1,2,4,5‐tetracarboxylic acid (pyromellitic acid) 43, mordant red‐19 44, and oxine 28,45. Many of these procedures suffer from interferences by several coexisting metal ions 25–35.…”

Cloud point extraction associated with differential pulse voltammetry: preconcentration and determination of trace uranyl in natural water

“…Electrochemical techniques are attractive for the detection of trace metal ions due to their high sensitivity, low cost, rapid analysis process and suitability for on-site analysis. [28][29][30][31][32] However, some methods of electrochemical analysis for uranium still suffer from interference from co-existing ions, [33][34][35] such as Cu(II), Pb(II), V(IV), etc. A pretreatment method is also necessary for the preconcentration and purification of uranium before detection.…”