Voltammetrische Bestimmung von Coffein in Kaffee, Tee und coffeinhaltigen Getr�nken

Sontag, Gerhard; Kral, Karl

doi:10.1007/bf01196409

Cited by 14 publications

(2 citation statements)

References 14 publications

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“…proposed a simple method for the electroanalysis of caffeine, using a platform made of gold nanoparticles (AuNPs) developed in a chitosan matrix in the presence of oxalic acid on gold electrode . However, the high positive oxidation potential of caffeine limits the use of common electrodes such as glassy carbon electrode and carbon paste electrode . Nafion is a perfluorinated sulphonated cation exchanger widely used as electrode modifier due to its antifouling capacity, chemical inertness and preconcentration features.…”

Section: Introductionmentioning

confidence: 99%

Electrochemical Sensor for Caffeine Based on a Glassy Carbon Electrode Modified with an Attapulgite/Nafion Film

et al. 2018

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In the present work, a simple and economic analytical method based on attapulgite/nafion coated glassy carbon electrode (AT/Naf/GCE) has been developped for the electrochemical determination of caffeine. Prior to its use, the ionic exchange properties and conductivity of AT/Naf/GCE were studied by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Caffeine gave an irreversible oxidation peak around +1.41 V (vs Ag/AgCl reference electrode) in 0.1 M H2SO4 at pH 1.5. The peak current varied linearly with the square root of the scan rate, showing that the transfer process is controlled by diffusion. The heterogeneous rate constant, the transfer coefficient and the number of electrons involved were calculated. Upon optimization of key analytical parameters involved in the electroanalysis of caffeine by DPV, the recorded oxidation peak current varied linearly with caffeine concentration in the range from 0.1 to 4 μm, leading to a detection limit of 4.57×10−8 M (S/N=3). The developed electrode exhibited good stability and was easily regenerated. The effect of some important potential interfering compounds (ascorbic acid, dopamine, uric acid, sulphite ions and glucose) on the signal of caffeine was also examined. The obtained electrode was successfully employed in the determination of caffeine content in a commercial drug.

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Section: Introductionmentioning

confidence: 99%

Electrochemical Sensor for Caffeine Based on a Glassy Carbon Electrode Modified with an Attapulgite/Nafion Film

et al. 2018

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“…+ ) with water followed by deprotonation and further oxidation. Although there are many other electrochemical studies examining CAF for quantification purposes in aqueous media using carbon electrodes,18, 19 modified carbon electrodes20–23 and potentiometric means,24, 25 there are currently no reports in an aprotic organic medium.…”

Section: Introductionmentioning

confidence: 99%

Electrochemically Controlled One‐Electron Oxidation Coupled to Consecutive Hydrogen Atom Transfer of Caffeine

Chan

Ganguly

et al. 2014

ChemElectroChem

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Caffeine (CAF) undergoes a one‐electron oxidation in acetonitrile to form a cation radical, with variable scan rate CV experiments indicating that the lifetime of the cation radical improves as the trace water content of the solvent is decreased. Electrochemical oxidation (and chemical oxidation with NOSbF6) of CAF in CH3CN leads to the generation of the protonated CAF cation as the long‐term product in high yield, whose structure is confirmed by single‐crystal X‐ray crystallography and NMR spectroscopy. The protonated cation is able to be electrochemically reduced back to CAF under electrolysis conditions. The formation of the protonated cation involves the initial one‐electron oxidation of CAF to form the cation radical, which undergoes a hydrogen atom abstraction reaction. Digital simulations of the CV data show that the rate and equilibrium constants for the hydrogen atom abstraction step are kf=1.0×102 L mol−1 s−1 and Keq=1.0×102.

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Electrochemical methods for food and drink analysis

Mannino

Wang

1992

Electroanalysis

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This review article assesses the status of electroanalysis in the food industry. Modern trends in electroanalysis, which offer unique possibilities for assays of foods and drinks, and for nionitoring food production processes, are discussed, Particular attention is given to the utility of new bincatalytic sensors, stripping techniques, and electrochemical flow detectors in the food industry. More than 90 references are given and future prospects are discussed.

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Voltammetrische Bestimmung von Coffein in Kaffee, Tee und coffeinhaltigen Getr�nken

Cited by 14 publications

References 14 publications

Electrochemical Sensor for Caffeine Based on a Glassy Carbon Electrode Modified with an Attapulgite/Nafion Film

Electrochemical Sensor for Caffeine Based on a Glassy Carbon Electrode Modified with an Attapulgite/Nafion Film

Electrochemically Controlled One‐Electron Oxidation Coupled to Consecutive Hydrogen Atom Transfer of Caffeine

Electrochemical methods for food and drink analysis

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