Scanned stripping chronopotentiometry at bismuth film rotating disc electrodes: a method for quantitative dynamic metal speciation

2014 ◽  
Vol 11 (2) ◽  
pp. 150 ◽  
Author(s):  
Jose Paulo Pinheiro ◽  
Luciana S. Rocha ◽  
Danielle Goveia ◽  
Raewyn M. Town
Keyword(s):  
Metal Speciation ◽  
Speciation Analysis ◽  
Deposition Potential ◽  
Bismuth Film ◽  
Rotating Disc ◽  
Stripping Chronopotentiometry ◽  
Mercury Electrodes ◽  
Disc Electrodes ◽  
Bismuth Electrodes

Environmental context Electroanalytical methods have found wide application in trace metal speciation analysis in environmental systems. The need to find functional alternatives to mercury electrodes for in situ speciation studies has encouraged the use of bismuth as a solid-state electrode substrate. We demonstrate the utility of bismuth electrodes for quantitative dynamic speciation analysis. Abstract Bismuth film electrodes are employed for dynamic metal speciation analysis of PbII complexes by stripping chronopotentiometry at scanned deposition potential (SSCP). Their performance is found to be comparable to that of mercury-film electrodes. The quantitative SSCP expressions that describe the thermodynamic and kinetic complexation parameters are straightforwardly applicable to this solid electrode.

Dynamic Speciation Analysis of Heterogeneous Metal Complexes with Natural Ligands by Stripping Chronopotentiometry at Scanned Deposition Potential (SSCP)

2004 ◽  
Vol 57 (10) ◽  
pp. 983 ◽  
Author(s):  
Raewyn M. Town ◽  
Herman P. van Leeuwen
Keyword(s):  
Metal Complexes ◽  
Humic Substances ◽  
Metal Binding ◽  
Metal Speciation ◽  
Speciation Analysis ◽  
Deposition Potential ◽  
Stripping Chronopotentiometry ◽  
Determination Of Parameters ◽  
Apparent Stability

Stripping chronopotentiometry at scanned deposition potential (SSCP) allows chemical heterogeneity in metal speciation to be unambiguously identified. In the labile regime, use of the Freundlich binding isotherm allows straightforward determination of parameters to describe the apparent stability and heterogeneity of metal complexes with humic substances. The extent of heterogeneity of metal binding by several humic substances follows the order Cu(ii) >> Pb(ii) > Cd(ii). The lability of metal complexes decreases from the foot to the top of the wave, and the greater the degree of heterogeneity, the more readily lability is lost. In the kinetic current regime, the Koutecký–Koryta approximation allows an expression to be obtained for the SSCP wave that provides a good estimate of the experimental data for metal complexes with moderate degrees of heterogeneity.

Lead electrochemical speciation analysis in seawater media by using AGNES and SSCP techniques

2014 ◽  
Vol 11 (2) ◽  
pp. 137 ◽  
Author(s):  
Margarita Díaz-de-Alba ◽  
M. Dolores Galindo-Riaño ◽  
José Paulo Pinheiro
Keyword(s):  
Natural Organic Matter ◽  
Metal Ion ◽  
Metal Speciation ◽  
Speciation Analysis ◽  
Deposition Potential ◽  
Visual Minteq ◽  
Ph Values ◽  
Stripping Chronopotentiometry ◽  
Theoretical Predictions ◽  
Free Metal

Environmental context Metal contamination of seawater can present severe environmental problems owing to the high toxicity of metals and their persistence in the environment. This study explores the possibility of analysing lead in seawater media using two recently developed electrochemical methods. The methods are shown to be very useful tools to monitor the behaviour and fate of lead and other metals in seawater. Abstract The speciation of PbII in synthetic and real seawater is studied by absence of gradients and Nernstian equilibrium stripping (AGNES) and stripping chronopotentiometry at scanned deposition potential (SSCP). The usefulness of the combination of both techniques in the same electrochemical cell for trace metal speciation analysis is assessed at different pH values (2.7, 5.0, 6.0, 7.0 and 8.6). The AGNES (free metal ion concentrations) and SSCP (stability constants) results for synthetic seawater agree reasonably with each other and with the theoretical predictions of the software Visual MINTEQ 3.0. This is also true for real seawater media below pH 7.0. Because of the influence of natural organic matter (2.01mgL–1 total organic carbon) in the real seawater at pH 7.0 and 8.6 the SSCP signal showed that the PbII complexes became less labile and were formed by chemically heterogeneous ligands. At these pH values, free metal concentrations determined by AGNES agreed with concentrations predicted by Visual MINTEQ using a generic fulvic acid concentration.

scholarly journals Determination of Chromium in Natural Water by Adsorptive Stripping Voltammetry Using In Situ Bismuth Film Electrode

2020 ◽  
Vol 2020 ◽  
pp. 1-15 ◽  
Author(s):  
Nguyen Thị Hue ◽  
Nguyen Van Hop ◽  
Hoang Thai Long ◽  
Nguyen Hai Phong ◽  
Tran Ha Uyen ◽  
...  
Keyword(s):  
Glassy Carbon ◽  
Natural Water ◽  
Deposition Time ◽  
Stripping Voltammetry ◽  
Differential Pulse ◽  
Deposition Potential ◽  
Adsorptive Stripping Voltammetry ◽  
Film Electrode ◽  
Bismuth Film

Development of adsorptive stripping voltammetry (AdSV) combined with in situ prepared bismuth film electrode (in situ BiFE) on glassy carbon disk surface using diethylenetriamine pentaacetic acid (DTPA) as a complexing agent and NO3− as a catalyst to determine the trace amount of chromium (VI) is demonstrated. According to this method, in the preconcentration step at Edep = −800 mV, the bismuth film is coated on the surface of glassy carbon electrodes simultaneously with the adsorption of complexes Cr(III)-DTPA. In addition to the influencing factors, the stripping voltammetry performance factors such as deposition potential, deposition time, equilibration time, cleaning potential, cleaning time, and technical parameters of differential pulse and square wave voltammetries have been investigated, and the influence of Cr(III), Co(II), Ni(II), Ca(II), Fe(III), SO42−, Cl−, and Triton X has also been investigated. This method gained good repeatability with RSD <4% (n = 9) for the differential pulse adsorptive stripping voltammetry (DP-AdSV) and RSD < 3% (n = 7) for the square wave adsorptive stripping voltammetry (SqW-AdSV), and low limit of detection: LOD = 12.10−9 M ≈ 0.6 ppb (at a deposition potential (Edep) of −800 mV and the deposition time (tdep) of 50 s) and LOD = 2.10−9 M ≈ 0.1 ppb (at Edep = −800 mV and tdep = 160 s) for the DP-AdSV and SqW-AdSV, respectively. This method has been successfully applied to analyze chromium in natural water.

scholarly journals Electroanalytical Determination of Cadmium(II) and Lead(II) Using an in-situ Bismuth Film Modified Edge Plane Pyrolytic Graphite Electrode

2007 ◽  
Vol 23 (3) ◽  
pp. 283-289 ◽  
Author(s):  
Roohollah Torabi KACHOOSANGI ◽  
Craig E. BANKS ◽  
Xiaobo JI ◽  
Richard G. COMPTON
Keyword(s):  
Graphite Electrode ◽  
Pyrolytic Graphite ◽  
Bismuth Film ◽  
Pyrolytic Graphite Electrode
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