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

• Published in: Food chemistry Vol. 135; no. 3; pp. 1198 - 1204
• Main Authors: Švorc, L’ubomír, Tomčík, Peter, Svítková, Jana, Rievaj, Miroslav, Bustin, Dušan
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.12.2012; Elsevier
• Subjects: 1,3,7-Trimethylxantine; Beverages; Beverages - analysis; Biological and medical sciences; Boron-doped diamond electrode; Caffeine; Caffeine - analysis; Diamond - chemistry; Electrochemistry - instrumentation; Electrochemistry - methods; Electrodes; Electrolytes; Food industries; Fundamental and applied biological sciences. Psychology; Limit of Detection; Oxidation; Oxidation-Reduction; Samples; Statistical analysis; Statistical methods; Voltammetry; Voltammetry; 1,3,7-Trimethylxantine; Boron-doped diamond electrode; Caffeine; Electrodes; Sample; Beverage
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2012.05.052

► Unmodified BDD electrode=sensitive electrochemical sensor for caffeine determination. ► Simple, rapid and accurate technique in comparison with other analytical methods. ► Selective method, species present in beverages do not interfere in high excess. ► Green possibility for quality control analysis of food products. ► Irreversibility of caffeine electrooxidation is electrochemically confirmed. 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 2.5×10−5M, good repeatability (RSD of 2.1%) and detection limit of 1.5×10−7M 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.