Adsorption stripping voltammetry of phenol at Nafion-modified glassy carbon electrode in the presence of surfactants

Yi, Hongchao

doi:10.1016/s0039-9140(01)00531-8

Cited by 120 publications

(49 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The surface phenomenon observed with some kinds of solid state electrodes is not of great relevance here, however, DA could not be determined by voltammetry employing a mercury electrode, owing to the fact that the oxidation of the compound occurs at a potential more positive than that for mercury oxidation. [15][16][17] In preliminary studies, it was verified that cyclic voltammograms, employing the mercury electrode, made in the presence of citrate produced a well defined peak in the anodic scan for DA, which appears at a lower potential than that for mercury oxidation. 18 Based on this observation, an investigation of the electrochemical behavior of DA the mercury electrode in the presence of carboxylic compounds is presented.…”

Section: Introductionmentioning

confidence: 91%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Effect of carboxylate compounds on the electrochemical behavior of dopamine at a mercury electrode

Winter

Carvalho

Kubota

et al. 2003

J. Braz. Chem. Soc.

View full text Add to dashboard Cite

A oxidação eletroquímica da dopamina leva à deposição de filmes poliméricos sobre a superfície de eletrodos sólidos, diminuindo a atividade dos mesmos. No eletrodo de mercúrio o processo redox ocorre na região de potencial de oxidação do mercúrio. No entanto, na presença de compostos carboxílicos o voltamograma cíclico da dopamina, no eletrodo de mercúrio, é diferenciado e apresenta um novo produto eletroativo proveniente do processo de oxidação da dopamina. O presente trabalho descreve resultados preliminares sobre o comportamento eletroquímico da dopamina no eletrodo de mercúrio na presença de acetato, citrato e EDTA.The electrochemical oxidation of dopamine leads to deposition of polymeric films on the surfaces of solid state electrodes, decreasing the electrode activity. With a mercury electrode, the oxidation of dopamine occurs in the potential region of mercury oxidation. However, in the presence of carboxylic compounds the cyclic voltammogram of dopamine is different and presents a new electroactive product resulting from the oxidation of dopamine. This work describes preliminary results for the electrochemical behavior of dopamine at the Hg-electrode in the presence of acetate, citrate and EDTA. Keywords: dopamine, electrochemical behavior, carboxylate compounds, mercury electrode IntroductionOver the last 50 years a considerable number of reports about the electrochemical behavior of catecholamines and other biogenic amines has been described in the literature. [1][2][3] Interest in the redox behavior of catecholamines is related to the fact that some of these compounds are directly involved in neurotransmition processes. Several neurological disorders, in particular Parkinson's disease, are associated with improper catecholamine (dopamine) regulation. 4 New research on the pathology and treatment of these diseases requires the development of new analytical methods for dopamine (3,4-dihydroxyphenylethylamine) determination. Dopamine (DA) is an unstable phenolic compound, which undergoes oxidation in neutral or alkaline solutions in the presence of oxygen, with the formation of dopaminochrome and other polymeric compounds. [5][6][7] Several methods have been reported for the determination of dopamine, including spectrophotometry, 8 spectrofluorimetry, 9 radioimmunoassay 10 and high performance liquid chromatography with electrochemical detection. 11 In spite of the electrochemical activity of dopamine, electrochemical methods, due to their high sensitivity, are of special interest in the quantification of DA. 12 However, the electrochemical determination of phenolic compounds presents some problems due to the loss of electrode activity of some solid state electrodes, like platinum, glassy carbon and pyrolytic graphite, during the oxidation process. This electrode inactivation may be explained by the accumulation of reaction products, forming electro-polymerized films on the surface of the electrode. In order to reduce the phenomenon of electrode poisoning, modified electrodes for catecholamine determinat...

show abstract

Section: Introductionmentioning

confidence: 91%

Section: Introductionmentioning

confidence: 99%

Effect of carboxylate compounds on the electrochemical behavior of dopamine at a mercury electrode

Winter

Carvalho

Kubota

et al. 2003

J. Braz. Chem. Soc.

View full text Add to dashboard Cite

show abstract

“…showed that the electrochemical responses of these compounds were greatly enhanced in the presence of trace surfactant types [12][13][14][15][16].…”

Section: Insights In Analytical Electrochemistry Issn 2470-9867mentioning

confidence: 99%

Sodium Alpha Olefin Sulfonate Modified Carbon Paste Electrode Sensor for Dopamine: A Voltammetric Study

Cc¹,

Be²

2016

Insights Anal Electrochem

View full text Add to dashboard Cite

Sodium alpha olefin sulfonate, an anionic surfactant was modified in carbon paste electrode by immobilization technique. The surfactant modified carbon paste electrode (SAOS/MCPE) was applied for the electrochemical determination of dopamine. The modified electrode shows excellent electrocatalytic property towards DA at pH 7.2 in Phosphate Buffer solution (PBS). The effects of scan rate and concentration of dopamine was studied and the electrode process was adsorptioncontrolled processes. The modified electrode resolves the well-defined two peaks for dopamine and ascorbic acid which is absent for bare carbon paste electrode and simultaneous studies was studied by cyclic and differential pulse voltammetric techniques. The detection limit was found to be 1.051 × 10 -6 M respectively and the modified electrode shows good sensitivity and selectivity for dopamine.

show abstract

“…The adsorption of surfactants onto surface electrode as well as the solubilization of electrochemically active compounds into micelle aggregates may mediate catalytic systems, allowing significant change in redox potential and charge transfer and diffusion coefficients of the electrode processes can be observed. [22][23][24] Szymula and Narkiewicz-Michalez 25 reported the behavior of electrochemical oxidation of ascorbic acid in aqueous solution with anionic and cationic surfactants, verifying significant changes in the oxidation peak potential as well as in the peak current value, mainly due to the surfactant film formed at the electrode/solution interface. According to authors, the negatively charged ascorbic acid has a tendency to accumulate in the positively charged crown of cationic micelles, which enhances the rate of oxidation and consequently provoking an increase in the peak current.…”

Section: Introductionmentioning

confidence: 96%

Micelle-mediated method for simultaneous determination of ascorbic acid and uric acid by differential pulse voltammetry

Reis¹,

Tarley²,

Kubota³

2008

J. Braz. Chem. Soc.

View full text Add to dashboard Cite

O presente trabalho descreve uma metodologia analítica para determinação simultânea de ácido ascórbico (AA) e ácido úrico (AU) por voltametria de pulso diferencial empregando o surfactante catiônico cloreto de cetilpiridínio. Medidas voltamétricas de pulso diferencial realizadas em pH 7,0 revelaram que o meio micelar catiônico permite separar em 282 mV os picos de oxidação de AA e AU na mesma solução, valor suficiente para determinar ambas as espécies simultaneamente. Como em pH 7,0 o AA está mais ionizado que o AU, sua atração eletrostática em direção às micelas catiônicas, formadas sobre a superfície do eletrodo de carbono vítreo, é maior; desta forma, promove a diminuição no sobrepotencial e o aumento na taxa de transferência de elétrons. Foram construídas curvas de calibração para AA e AU na faixa de concentração de 4,70 até 220 µmol L -1 e 0,50 até 110 µmol L -1 . A metodologia proposta foi aplicada para a determinação de AA e AU em amostras de urina humana.The present work describes an analytical methodology for simultaneous determination of ascorbic acid (AA) and uric acid (UA) by differential pulse voltammetry employing the cationic surfactant, cetylpyridinium chloride. Differential pulse voltammetry measurements revealed that the cationic micellar media may separate the oxidation peak potentials of AA and UA present in the same solution by about 282 mV, which is enough to determine both species simultaneously. As in pH 7.0 the AA is more ionized than UA, its electrostatic attraction towards the cationic micelles formed onto the surface of glassy carbon electrode is higher, therefore, promoting a decrease in the overpotential and increasing the electron transfer rate. Calibration curves to AA and UA in the concentration range from 4.70 up to 220 µmol L -1 and 0.50 up to 110 µmol L -1 were built. The proposed methodology was applied for the simultaneous determination of AA and UA in human urine samples.Keywords: uric acid, ascorbic acid, differential pulse voltammetry, cationic surfactant, micelles IntroductionAscorbic acid (AA) and uric acid (UA) coexist in biological fluids such as blood and urine, 1 being in practical medicine, necessary to determine AA and UA simultaneously. Ascorbic acid (a water soluble vitamin C) plays a vital role in processes of oxidation and reduction in the human organism by participating in many metabolic reactions. 2 AA has also been used to prevent and treat the common cold, mental illness, infertility and cancer. 3 Moreover, ascorbic acid has also been used clinically in the treatment and prevention of scurvy. 4 Uric acid (2,6,8-trihydroxypurine, UA) is the primary product of purine metabolism in the human body and is formed in liver and tissues during the oxidation of aminopurines. 5 Its abnormal concentration level in urine and serum are symptoms of several diseases like gout, hyperuricaemia and Lesch-Nyhan syndrome. 6,7 For instance, the concentration of uric acid in the blood of patients suffering from gout increases up to 1 mmol L -1 , which is above the concentration ...

show abstract

Adsorption stripping voltammetry of phenol at Nafion-modified glassy carbon electrode in the presence of surfactants

Cited by 120 publications

References 8 publications

Effect of carboxylate compounds on the electrochemical behavior of dopamine at a mercury electrode

Effect of carboxylate compounds on the electrochemical behavior of dopamine at a mercury electrode

Sodium Alpha Olefin Sulfonate Modified Carbon Paste Electrode Sensor for Dopamine: A Voltammetric Study

Micelle-mediated method for simultaneous determination of ascorbic acid and uric acid by differential pulse voltammetry

Contact Info

Product

Resources

About