Application of Controlled Potential Techniques to Study of Rapid Succeeding Chemical Reaction Coupled to Electro-Oxidation of Ascorbic Acid

Perone, S. P.; Kretlow, W. J.

doi:10.1021/ac60244a034

Cited by 95 publications

(51 citation statements)

References 17 publications

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“…Therefore, pH 5 was chosen as optimum value. In the case of AA, an almost detailed study was achieved, since the electrochemical oxidation of AA in aqueous solutions is a well-known reaction that occurs in two successive steps [43]. The first step corresponds in overall to a reversible two-electron, two-proton process, producing the unstable compound II.…”

Section: Determination Of Optimum Ph For Catalyticmentioning

confidence: 99%

Preparation and Electrochemical Study of Fisetin Modified Glassy Carbon Electrode. Application to the Determination of NADH and Ascorbic Acid

Golabi

Irannejad

2005

Electroanalysis

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A new modified electrode, FMGCE, was prepared by electrodeposition of fisetin (F) at the surface of a preactivated glassy carbon electrode. Cyclic voltammetry was used to investigate the electrochemical properties of this electrode. The charge transfer rate constant, k s , and transfer coefficient, a s , for electron transfer between electrode substrate and surface deposited F were calculated as 16.34 s À1 and 0.54, respectively. The electrode ability towards the electrocatalytic oxidation of dihydronicotinamide adenine dinucleotide (NADH) and ascorbic acid (AA) was also studied using cyclic voltammetry and chronoamperometry as diagnostic techniques. The catalytic currents of NADH and AA were used for determination of heterogeneous rate constant, k h , of these substrates oxidation at the surface of modified electrode. The diffusion coefficients of both substrates were also estimated using chronoamperometric results. Finally, FMGCE was used as voltammetric and amperometric sensors for determination of NADH and AA in quiet and moving solutions respectively. The calculated limit of detection of NADH and AA by voltammetry were 0.06 and 0.05 mM, respectively. While, these values decrease to 2.4 and 1.8 mM, respectively for an amperometric procedure. The latter method was used successfully for quantification of AA in some real samples.

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Section: Determination Of Optimum Ph For Catalyticmentioning

confidence: 99%

Preparation and Electrochemical Study of Fisetin Modified Glassy Carbon Electrode. Application to the Determination of NADH and Ascorbic Acid

Golabi

Irannejad

2005

Electroanalysis

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“…Since the oxidation product of ascorbic acid is only stable on the order of milliseconds [55,56], its influence on the amplified redox cycling current is expected to decay quickly inside the nanochannel. Figure 10b shows cyclic voltammograms from the reducing electrode obtained with a nF-IDE filled with 100 μM paracetamol and varying concentrations of ascorbic acid.…”

Section: Resultsmentioning

confidence: 99%

Redox cycling in nanofluidic channels using interdigitated electrodes

et al. 2009

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Amperometric detection is ideally suited for integration into micro-and nanofluidic systems as it directly yields an electrical signal and does not necessitate optical components. However, the range of systems to which it can be applied is constrained by the limited sensitivity and specificity of the method. These limitations can be partially alleviated through the use of redox cycling, in which multiple electrodes are employed to repeatedly reduce and oxidize analyte molecules and thereby amplify the detected signal. We have developed an interdigitated electrode device that is encased in a nanofluidic channel to provide a hundred-fold amplification of the amperometric signal from paracetamol. Due to the nanochannel design, the sensor is resistant to interference from molecules undergoing irreversible redox reactions. We demonstrate this selectivity by detecting paracetamol in the presence of excess ascorbic acid.

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“…The irreversible oxidation of ascorbic acid at carbon paste electrode has been studied earlier [40]. The electron-transfer step is fast but dehydroascorbic acid formed undergoes an irreversible hydration reaction with a rate constant of about 1.3×10 3 s -1 [41].…”

Section: Resultsmentioning

confidence: 99%

Carbon paste electrode modified with copper(II) phosphate immobilized in a polyester resin for voltammetric determination of l -ascorbic acid in pharmaceutical formulations

et al. 2003

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A carbon paste electrode modified with copper(II) phosphate immobilized in a polyester resin (CuP-Poly) is proposed for voltammetric determination of L-ascorbic acid in pharmaceutical formulations. The modified electrode allows the detection of L-ascorbic acid at lower anodic potentials than observed at unmodified electrodes. Several parameters that can influence the voltammetric response of the proposed electrode such as carbon paste composition, pH, scan rate, and possible interference were investigated. The peak current was proportional to the concentration of ascorbic acid in the range 2.0 x 10(-5) to 3.2 x 10(-3) mol L(-1) with a detection limit of 1.0 x 10(-5) mol L(-1). The stability and repeatability of the electrode for the determination of L-ascorbic acid are also discussed. Amperometric response was also recorded for electrocatalytic oxidation of the L-ascorbic acid. Concentrations of the vitamin C in pharmaceutical formulations (tablets) measured using the modified electrode and a titrimetric method are in agreement at the 95% confidence level and within an acceptable range of error.

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Application of Controlled Potential Techniques to Study of Rapid Succeeding Chemical Reaction Coupled to Electro-Oxidation of Ascorbic Acid

Cited by 95 publications

References 17 publications

Preparation and Electrochemical Study of Fisetin Modified Glassy Carbon Electrode. Application to the Determination of NADH and Ascorbic Acid

Preparation and Electrochemical Study of Fisetin Modified Glassy Carbon Electrode. Application to the Determination of NADH and Ascorbic Acid

Redox cycling in nanofluidic channels using interdigitated electrodes

Carbon paste electrode modified with copper(II) phosphate immobilized in a polyester resin for voltammetric determination of l -ascorbic acid in pharmaceutical formulations

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