Voltammetric determination of caffeine in beverage samples on bare boron-doped diamond electrode.

A sensitive and selective electrochemical method for the caffeine determination using bare boron-doped diamond electrode was developed. It was found that caffeine provided highly reproducible and well-defined irreversible oxidation peak at very positive potential. The effects of supporting electrolyte, pH and scan rate on the voltammetric response of caffeine oxidation were studied to select the optimum experimental conditions. Linear response of peak current on the concentration in the range from 4×10(-7) to 2.5×10(-5)M, good repeatability (RSD of 2.1%) and detection limit of 1.5×10(-7)M without any chemical modifications and electrochemical surface pretreatment were evaluated. The effect of possible interferents appeared to be negligible which evidently proved very good selectivity. The proposed method was successfully applied for the caffeine determination in commercially available beverage samples, with results in a close statistical agreement to those declared by manufacturer and HPLC used as independent method.

[1]  Herbert H. Hill,et al.  Ion mobility spectrometry for the rapid analysis of over-the-counter drugs and beverages , 2009, International journal for ion mobility spectrometry : official publication of the International Society for Ion Mobility Spectrometry.

[2]  R. Rocha‐Filho,et al.  Simultaneous voltammetric determination of paracetamol and caffeine in pharmaceutical formulations using a boron-doped diamond electrode. , 2009, Talanta.

[3]  P. Norouzi,et al.  Development of a voltammetric sensor based on a molecularly imprinted polymer (MIP) for caffeine measurement , 2010 .

[4]  J. P. Telo,et al.  Mechanism of Free Radical Oxidation of Caffeine in Aqueous Solution. , 1997 .

[5]  M. Spiteller,et al.  Determination of phenacetin and salophen analgetics in solid binary mixtures with caffeine by infrared linear dichroic and Raman spectroscopy. , 2008, Journal of pharmaceutical and biomedical analysis.

[6]  G. Mersal.  Experimental and Computational Studies on the Electrochemical Oxidation of Caffeine at Pseudo Carbon Paste Electrode and Its Voltammetric Determination in Different Real Samples , 2012, Food Analytical Methods.

[7]  P. Casati,et al.  Determination of Caffeine at a Nafion‐Covered Glassy Carbon Electrode , 2007 .

[8]  B. Rezaei,et al.  A new method based on electrospray ionisation ion mobility spectrometry (ESI-IMS) for simultaneous determination of caffeine and theophylline. , 2011, Food chemistry.

[9]  P. Gardinali,et al.  Trace determination of caffeine in surface water samples by liquid chromatography--atmospheric pressure chemical ionization--mass spectrometry (LC-APCI-MS). , 2002, Environment international.

[10]  A. García-Lafuente,et al.  Fast and simultaneous determination of phenolic compounds and caffeine in teas, mate, instant coffee, soft drink and energetic drink by high-performance liquid chromatography using a fused-core column. , 2011, Analytica chimica acta.

[11]  S. Ferro,et al.  Fabrication and application of Nafion®-modified boron-doped diamond electrode as sensor for detecting caffeine , 2010 .

[12]  Ke-Jing Huang,et al.  A graphene-based electrochemical sensor for sensitive determination of caffeine. , 2011, Colloids and surfaces. B, Biointerfaces.

[13]  R. Compton,et al.  Sono-cathodic stripping voltammetry of manganese at a polished boron-doped diamond electrode: application to the determination of manganese in instant tea. , 1999, The Analyst.

[14]  Jiewen Zhao,et al.  Identification of green tea's (Camellia sinensis (L.)) quality level according to measurement of main catechins and caffeine contents by HPLC and support vector classification pattern recognition. , 2008, Journal of pharmaceutical and biomedical analysis.

[15]  I. Berregi,et al.  Quantitative determination of caffeine, formic acid, trigonelline and 5-(hydroxymethyl)furfural in soluble coffees by 1H NMR spectrometry. , 2010, Talanta.

[16]  E. Yonemochi,et al.  Development of a method for the determination of caffeine anhydrate in various designed intact tablets [correction of tables] by near-infrared spectroscopy: a comparison between reflectance and transmittance technique. , 2008, Journal of pharmaceutical and biomedical analysis.

[17]  Á. Ríos,et al.  Automatic selective determination of caffeine in coffee and tea samples by using a supported liquid membrane-modified piezoelectric flow sensor with molecularly imprinted polymer , 2005 .

[18]  Karolina Pecková,et al.  Boron-Doped Diamond Film Electrodes—New Tool for Voltammetric Determination of Organic Substances , 2009 .

[19]  A. Mazumder,et al.  Determination of acidic drugs and caffeine in municipal wastewaters and receiving waters by gas chromatography-ion trap tandem mass spectrometry. , 2006, Journal of chromatography. A.

[20]  M. Turemis,et al.  An inhibition type alkaline phosphatase biosensor for amperometric determination of caffeine , 2010 .

[21]  A. Belay.  Measurement of integrated absorption cross-section, oscillator strength and number density of caffeine in coffee beans by integrated absorption coefficient technique. , 2010 .

[22]  C. Lunte,et al.  Determination of caffeine and its metabolites by micellar electrokinetic capillary electrophoresis. , 1997, Journal of chromatography. B, Biomedical sciences and applications.

[23]  F. Marken,et al.  Electroanalysis at diamond-like and doped-diamond electrodes , 2003 .

[24]  Li Jiang,et al.  Electroanalytical applications of boron-doped diamond microelectrode arrays. , 2006, Talanta.

[25]  S. Minteer,et al.  Effects of mixture casting Nafion® with quaternary ammonium bromide salts on the ion-exchange capacity and mass transport in the membranes , 2002 .

[26]  A. Kraft.  Doped Diamond: A Compact Review on a New, Versatile Electrode Material , 2007, International Journal of Electrochemical Science.

[27]  J. Sherma,et al.  Development and validation of a method for determination of caffeine in diuretic tablets and capsules by high-performance thin-layer chromatography on silica gel plates with a concentration zone using manual spotting and ultraviolet absorption densitometry. , 2005, Journal of AOAC International.

[28]  P. D. Tzanavaras,et al.  Development and validation of a high-throughput high-performance liquid chromatographic assay for the determination of caffeine in food samples using a monolithic column. , 2007, Analytica chimica acta.

[29]  R. Stubbs,et al.  Determination of caffeine and its metabolites in urine by capillary electrophoresis‐mass spectrometry , 2005, Electrophoresis.

[30]  R. Cotter,et al.  Mass Spectrometry , 1992, Bio/Technology.