Development of differential pulse voltammetric method for determining samarium (III) through electroanalytical study of the metal ion in acetonitrile using Box–Behnken design

Metal ion dyshomeostasis plays an important role in diseases, including neurodegeneration. Tau protein is a known neurodegeneration biomarker, but its interactions with biologically relevant metal ions, such as Cu(II), are not fully understood. Herein, the Cu(II) complexes of four tau R peptides, based on the tau repeat domains, R1, R2, R3, and R4, were characterized by electrochemical methods, including cyclic voltammetry, square-wave voltammetry, and differential pulse voltammetry in solution under aerobic conditions. The current and potential associated with Cu(II)/(I) redox couple was modulated as a function of R peptide sequence and concentration. All R peptides coordinated Cu(II) resulting in a dramatic decrease in the current associated with free Cu(II), and the appearance of a new redox couple due to metallo–peptide complex. The metallo–peptide complexes were characterized by the irreversible redox couple at more positive potentials and slower electron-transfer rates compared with the free Cu(II). The competition binding studies between R peptides with Cu(II) indicated that the strongest binding affinity was observed for the R3 peptide, which contained 2 His and 1 Cys residues. The formation of complexes was also evaluated as a function of peptide concentration and in the presence of competing Zn(II) ions. Data indicate that all metallo–peptides remain redox active pointing to the potential importance of the interactions between tau protein with metal ions in a biological setting.

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Copper Complexing Capacity and Trace Metal Content in Common and Balsamic Vinegars: Impact of Organic Matter

Molecules ◽

10.3390/molecules25040861 ◽

2020 ◽

Vol 25 (4) ◽

pp. 861

Author(s):

Sotirios Karavoltsos ◽

Aikaterini Sakellari ◽

Vassilia J. Sinanoglou ◽

Panagiotis Zoumpoulakis ◽

Marta Plavšić ◽

...

Keyword(s):

Organic Matter ◽

Metal Ions ◽

Metal Ion ◽

Metal Speciation ◽

Anodic Stripping Voltammetry ◽

Stripping Voltammetry ◽

Differential Pulse ◽

Transition Metal Ions ◽

Electrochemical Technique ◽

Mass Unit

Complex formation is among the mechanisms affecting metal bioaccessibility. Hence, the quantification of organic metal complexation in food items is of interest. Organic ligands in solutions of environmental and/or food origin function as buffering agents against small changes in dissolved metal concentrations, being able to maintain free metal ion concentrations below the toxicity threshold. Organic matter in vinegars consists of bioactive compounds, such as polyphenols, Maillard reaction endproducts, etc., capable of complexing metal ions. Furthermore, transition metal ions are considered as micronutrients essential for living organisms exerting a crucial role in metabolic processes. In this study, differential pulse anodic stripping voltammetry (DPASV), a sensitive electrochemical technique considered to be a powerful tool for the study of metal speciation, was applied for the first time in vinegar samples. The concentrations of Cu complexing ligands (LT) in 43 vinegars retailed in Greece varied between 0.05 and 52 μM, with the highest median concentration determined in balsamic vinegars (14 μM), compared to that of common vinegars (0.86 μM). In 21% of the vinegar samples examined, LT values were exceeded by the corresponding total Cu concentrations, indicating the presence of free Cu ion and/or bound within labile inorganic/organic complexes. Red grape balsamic vinegars exhibited the highest density of Cu ligands per mass unit of organic matter compared to other foodstuffs such as herbal infusions, coffee brews, and beers. Among the 16 metals determined in vinegars, Pb is of particular importance from a toxicological point of view, whereas further investigation is required regarding potential Rb biomagnification.

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The use of differential pulse anodic stripping voltammetry and diffusive gradient in thin films for heavy metals speciation in soil solution

Open Chemistry ◽

10.2478/s11532-007-0060-6 ◽

2008 ◽

Vol 6 (1) ◽

pp. 71-79 ◽

Cited By ~ 7

Author(s):

Jana Dytrtová ◽

Ivana Šestáková ◽

Michal Jakl ◽

Jiřina Száková ◽

Daniela Miholová ◽

...

Keyword(s):

Thin Films ◽

Heavy Metals ◽

Soil Solution ◽

Metal Ion ◽

Plant Biomass ◽

Anodic Stripping Voltammetry ◽

Total Content ◽

Stripping Voltammetry ◽

Differential Pulse ◽

Anodic Stripping

AbstractIn the soil solutions obtained in situ with suction cups from soils (Cambisol and Fluvisol) of pot experiment with Salix smithiana Smith, Lolium perenne L. and Thlaspi caerulescens J. & C. Presl heavy metals species (Cd, Pb and Cu) were assayed by differential pulse anodic stripping voltammetry and diffusive gradient in thin films. Prediction of accumulation performed best at free metal ion concentrations in unchanged pH (in 10−3 mol L−1 NaClO4 base electrolyte). The speciation provided by differential pulse anodic stripping voltammetry according to pH can provide a detailed description of the soil solution matrix. The concentration of free metals in unchanged pH represents a small part of the total content and varied from 0.04 to 0.75% with two exceptions found for accumulating plants (the content of Cd2+ in the soil solution from T. caerulescens was about 6% and the content of Cu2+ in the soil solution from S. smithiana was about 30%). The available concentration as determined by diffusive gradient in thin films was not in correlation with the heavy metals concentration in plant biomass.

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Voltammetric Methods in Metallothionein Research

Bioinorganic Chemistry and Applications ◽

10.1155/bca.2005.43 ◽

2005 ◽

Vol 3 (1-2) ◽

pp. 43-53 ◽

Cited By ~ 27

Author(s):

Ivana Šestáková ◽

Tomáš Navrátil

Keyword(s):

Metal Ion ◽

Composite Electrode ◽

Differential Pulse ◽

Carbon Composite ◽

Ion Transfer ◽

Adsorbed State ◽

Carbon Composite Electrode ◽

Pulse Voltammetry ◽

Voltammetric Methods

The application of voltammetric methods using different rates of polarisation on HMDE reveal inert or labile behaviour of Cd- or Zn- complexes in the presence of excessive cadmium or zinc ions in solution. This phenomenon was demonstrated first on the simplest phytochelatin – complex of peptide(γ-Glu-Cys)2Glywith cadmium, later on rabbit liver metallothioneins –Cd7MTin the presence of cadmium andCd5Zn2MTin the presence of zinc. Voltammetric methods can distinguish between labile and inert complexes present simultaneously and therefore could elucidate their role in reactions of metal ion transfer.Another method using different rates of polarisation – elimination voltammetry with linear scan – proved that S-tetracoordinated complexes of Cd(II) or Zn(II) in the above-mentioned metallothioneins on HMDE are reduced in the adsorbed state. This implies the possibility of increasing the sensitivity of identification or determination of the above complexes. On carbon composite electrode, similar behaviour of Cd-complexes as on HMDE was observed using differential pulse voltammetry.

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A novel differential pulse voltammetric method on rotating Au-disk electrode for the study of Hg2+ binding

Journal of Electroanalytical Chemistry ◽

10.1016/j.jelechem.2009.02.012 ◽

2009 ◽

Vol 629 (1-2) ◽

pp. 169-179 ◽

Cited By ~ 14

Author(s):

Elena Chekmeneva ◽

José Manuel Díaz-Cruz ◽

Cristina Ariño ◽

Miquel Esteban

Keyword(s):

Differential Pulse ◽

Disk Electrode ◽

Voltammetric Method

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A differential pulse voltammetric method for submicromolar determination of antihistamine drug desloratadine using an unmodified boron-doped diamond electrode

Analytical Methods ◽

10.1039/c9ay02785h ◽

2020 ◽

Vol 12 (8) ◽

pp. 1115-1121 ◽

Cited By ~ 2

Author(s):

Kayque Y. H. Nagao ◽

Carlos A. R. Salamanca-Neto ◽

Bruna Coldibeli ◽

Elen R. Sartori

Keyword(s):

Human Urine ◽

Differential Pulse ◽

Urine Samples ◽

Boron Doped Diamond ◽

Voltammetric Method ◽

Diamond Electrode ◽

Boron Doped ◽

Boron Doped Diamond Electrode ◽

Antihistamine Drug

A very sensitive voltammetric method for DESL using a BDDE was developed and applied to pharmaceutical, water and human urine samples.

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Determination of Trace Metal Ions in Common Salt by Stripping Voltammetry

Journal of AOAC International ◽

10.1093/jaoac/82.6.1413 ◽

1999 ◽

Vol 82 (6) ◽

pp. 1413-1418 ◽

Cited By ~ 6

Author(s):

Azza M M Ali

Keyword(s):

Metal Ion ◽

Supporting Electrolyte ◽

Standard Addition ◽

Stripping Voltammetry ◽

Differential Pulse ◽

Ion Concentration ◽

Common Salt ◽

Trace Metal Ions

Abstract Sensitive voltammetric methods using cathodic and anodic differential pulse stripping techniques were applied for determination of trace ions cadmium(II), cobalt(II), copper(II), lead(II), manganese(II), nickel(II), and zinc(II), which are usually found in different grades of common salt as contaminants. The optimal conditions, i.e., deposition time, preconcentration potential, supporting electrolyte, and ionic strength, were investigated for each metal ion. Concentration of the metal ion was determined by the standard addition method. Metal content varied according to the quality of the table salt.

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A Box-Behnken Optimized Methodology for the Quantification of Diclofenac using a Carbon Paste-Multiwalled Carbon Nanotubes Electrode

Current Analytical Chemistry ◽

10.2174/1573411014666180423151749 ◽

2019 ◽

Vol 15 (3) ◽

pp. 294-304 ◽

Cited By ~ 3

Author(s):

Miriam Franco Guzmán ◽

Luis Humberto Mendoza Huizar ◽

Carlos Andrés Galán Vidal ◽

Gabriela Roa Morales ◽

Giaan A. Álvarez Romero

Keyword(s):

Statistical Analysis ◽

Differential Pulse Voltammetry ◽

Heart Diseases ◽

Differential Pulse ◽

Carbon Paste ◽

Multiwalled Carbon ◽

Box Behnken Design ◽

Frequent Consumption ◽

Pulse Voltammetry ◽

High Concentrations

Background: Diclofenac is a widely used nonsteroidal anti-inflammatory drug. Recent studies have shown that frequent consumption of this drug in high concentrations can cause heart diseases, so strict control of diclofenac’s quantity in commercial drugs is necessary. This paper presents the development of an optimized voltammetric methodology for the quantification of diclofenac, which offers some advantages over other electrochemical and accepted methods. Objective: Optimize with a Box-Behnken design the differential pulse voltammetry parameters towards the quantification of diclofenac in pharmaceutical samples. Methods: Diclofenac behavior in the working electrode was evaluated by cyclic voltammetry, in order to stablish the best conditions for diclofenac’s quantification. A Box-Behnken design was then used to optimize the differential pulse voltammetry parameters and stablish the analytical behavior of the proposed methodology. Commercial tablets were prepared for analysis according to the Pharmacopeia, the DPV optimized methodology was used to quantify diclofenac in the samples, and the results were statistically compared with those obtained with the official methodology. Results: After optimization, the analytical parameters found were: correlation coefficient of 0.998, detection limit of 0.001 µM, quantification limit of 0.0033 µM and sensitivity of 0.299 µA.µM-1. The statistical analysis showed there were no significant differences between the results obtained with the proposed methodology and those obtained with the official methodology. Conclusion: The statistical analysis showed that the proposed methodology is as reliable as the official spectrophotometric one for the quantification of diclofenac in commercial drugs, with very competitive analytical parameters, and even better to others found with more complex electrodes.

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