The objective of this study was to exploit the advantages of stripping chronopotentiometry (SCP) and stripping chronopotentiometry at scanned deposition potential (SSCP) for trace metal speciation analyses by using thin-film mercury screen-printed electrodes (TMF-SPE). At first, the SCP parameters were optimised for TMF-SPE, in order to reach the complete depletion regime. It has been shown that a stripping current higher than or equal to 10 μA allows this regime to be attained without removing oxygen from the solution. Then, these analytical conditions were used for the construction of SSCP curves for Cd-PDCA and Cd-NTA. When the concentration of free ligand in solution was known, the knowledge of the model describing the SSCP curves in absence and presence of a complex and the use of an effective fitting tool enabled estimating the stability constant and the rate constants for complexation. Further studies with complexes of restricted mobility are however necessary to assess the usefulness of this procedure to also estimate the diffusion coefficient of the complexes. Besides, this study showed that this approach was valid even when ligands were not in excess at the electrode during stripping.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.aca.2010.12.034 | DOI Listing |
Biosensors (Basel)
November 2024
Université de Lorraine, CNRS, LIEC, F-54000 Nancy, France.
ACS Appl Mater Interfaces
March 2024
Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States.
Magnesium iodide (MgI) solid-electrolyte interface (SEI) layers have previously been shown to protect Mg metal anodes from passivation through products formed during Mg(TFSI) electrolyte decomposition (TSFI = trifluorosulfonimide). MgI formed from small quantities of I added to the electrolyte shows a drastic decrease in the overpotential for magnesium deposition and stripping. In this work, a MgI SEI layer was created in an fashion and then the electrochemical characteristics of this MgI SEI layer were probed both alone and with small quantities of I or BuNI additives to identify the electroactive species.
View Article and Find Full Text PDFBioelectrochemistry
June 2022
Institute of Biophysics, The Czech Academy of Sciences, v.v.i., Královopolská 135, 61265 Brno, Czech Republic. Electronic address:
In protein analysis, fast techniques applicable for preliminary tests of the protein structural changes are sought. We show that using constant current chronopotentiometric stripping peak H, small amounts of oligomeric, denatured and aggregated bovine serum albumin (BSA) can be easily distinguished from native form. Different behavior of native, denatured, and aggregated BSA could be explained by combination of their different adsorption at charged surface and accessibility of electroactive amino acid residues.
View Article and Find Full Text PDFMolecules
September 2021
Laboratoire Interdisciplinaire des Environnements Continentaux (LIEC), Université de Lorraine/CNRS, UMR7360, F54501 Vandœuvre-lès-Nancy, France.
Electrochemical stripping techniques are interesting candidates for carrying out onsite speciation of environmentally relevant trace metals due to the existing low-cost portable instrumentation available and the low detection limits that can be achieved. In this work, we describe the initial analytical technique method development by quantifying the total metal concentrations using Stripping Chronopotentiometry (SCP). Carbon paste screen-printed electrodes were modified with thin films of mercury and used to quantify sub-nanomolar concentrations of lead and cadmium and sub-micromolar concentrations of zinc in river water.
View Article and Find Full Text PDFAnal Chim Acta
July 2021
CNRS and Université de Lorraine, LCPME, UMR7564, Nancy, France. Electronic address:
A rapid and reliable oxygen elimination system was evaluated here for the electroanalytical study of metals. Dissolved oxygen was removed locally in the vicinity of a sensor by the means of electrochemical oxygen filter constructed from platinum grids. Three metals (Cd, Pb, and Zn) were determined by stripping chronopotentiometry (SCP) at a mercury film screen-printed electrode.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!