Exploiting micellar environment for simultaneous electrochemical determination of ascorbic acid and dopamine

Reis, A.; Tarley, César Ricardo Teixeira; Maniasso, Nelson; Kubota, Lauro T.

doi:10.1016/j.talanta.2005.04.011

Cited by 80 publications

(39 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The explanation of these behaviors can be assigned to the adsorption of the CPC micelles onto electrode surface forming a positively charged hydrophilic film oriented towards the water bulk phase, which may decrease the overpotential of the electrode and increase the electron transfer rate, as already previously demonstrated. 27 The cyclic voltamogram obtained for UA in the absence (dashed line) and in presence (solid line) of surfactant is shown in Figure 1B. As verified, in the presence of surfactant both anodic and cathodic peak currents present a slight increase, while anodic peak potential was shifted towards more negative values (293 to 249 mV).…”

mentioning

confidence: 52%

“…All experiments were carried out by fixing the concentration of CPC surfactant at 1.0 mmol L -1 according to previous work. 27 This value provides an enough concentration for covering the electrode surface by CPC surfactant, and consequently, the saturation of the adsorbed surfactant cannot affect the electrode oxidation process anymore, thus resulting in slight variation of E pa and I pa . …”

mentioning

confidence: 99%

See 1 more Smart Citation

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

mentioning

confidence: 52%

mentioning

confidence: 99%

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

show abstract

“…Therefore, the quick determination of dopamine in vitro and in living creatures has attracted considerable attention. [25][26][27][28] This paper proposes an electrochemical procedure employing an innovative, stable inorganic support.…”

Section: Introductionmentioning

confidence: 99%

Adsorption of a copper (II) complex on calcium phosphate intercalated with 4-aminobenzoic acid: synthesis and electrochemical investigation

Silva¹,

Souza²,

Santos³

et al. 2013

Quím. Nova

View full text Add to dashboard Cite

Recebido em 14/2/13; aceito em 9/5/13; publicado na web em 17/7/13In this study, the adsorption isotherm of copper (II) on a calcium phosphate host intercalated with 4-aminobenzoic acid in an ethanol solution was investigated. This gave a maximum adsorption capacity of 1.74 mmol g -1 . The material was incorporated into a carbonpaste electrode, and its electrochemical properties were investigated. However, for a dopamine solution, the anodic peak current increased owing to the electrocatalytic oxidation. The electrode presented the same response for at least 150 successive measurements, showing good repeatability. The modified electrode is very stable and reproducible. The electrode sensor was successfully applied for dopamine determination in pharmaceutical preparations.

show abstract

“…So far, many analytical methods, such as liquid chromatographic assay (2), capillary electrophoresis (3), spectrophotometry (4,5), spectrofluorimetry (6-9), electrochemical (10)(11)(12) and chemiluminescence (13) detection have been proposed for the determination of dopamine. Cyanuric chloride has special reaction performance and several triazine, containing only one active chlorine, reagents have been reported for the determination of methylamine, hydrogen peroxide, amino acids, phenol and oestrogens (14)(15)(16)(17)(18).…”

Section: Introductionmentioning

confidence: 99%

Spectrofluorimetric determination of dopamine using 1,5‐bis(4,6‐dicholro‐1,3,5‐triazinylamino) naphthalene

Wei¹,

Wang²,

Jiang³

2007

Luminescence

View full text Add to dashboard Cite

A new fluorescent reagent, 1,5-bis(4,6-dichloro-1,3,5-triazinylamino)naphthalene, containing two active chlorines, was synthesized by a one-step reaction. Under the optimum conditions for the determination of dopamine, the enhanced fluorescence intensity is proportional to the dopamine concentration. The fluorescence intensity was measured at lambda(ex/em) = 400/460 nm, with and without dopamine. The linear range and detection limit for the determination of dopamine were 1.0 x 10(-7) mol/L-5.0 x 10(-5) mol/L and 4.0 x 10(-8) mol/L. This method is simple, practical, can afford good precision and accuracy and can be successfully applied to assess dopamine in injections and human serum samples.

show abstract

Exploiting micellar environment for simultaneous electrochemical determination of ascorbic acid and dopamine

Cited by 80 publications

References 33 publications

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

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

Adsorption of a copper (II) complex on calcium phosphate intercalated with 4-aminobenzoic acid: synthesis and electrochemical investigation

Spectrofluorimetric determination of dopamine using 1,5‐bis(4,6‐dicholro‐1,3,5‐triazinylamino) naphthalene

Contact Info

Product

Resources

About