title: Voltammetric determination of caffeine in beverage samples on bare boron-doped diamond electrode.
abstract: 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.
authors.affiliation: Institute of Analytical Chemistry, Faculty of Chemical and Food Technology, Slovak University of Technology, Radlinského 9, Bratislava SK-812 37, Slovak Republic. lubomir.svorc@stuba.sk
authors.forename: L'ubomír
authors.initials: L
authors.lastname: Svorc
authors.forename: Peter
authors.initials: P
authors.lastname: Tomčík
authors.forename: Jana
authors.initials: J
authors.lastname: Svítková
authors.forename: Miroslav
authors.initials: M
authors.lastname: Rievaj
authors.forename: Dušan
authors.initials: D
authors.lastname: Bustin
mesh_terms: D001628:Beverages / Q000032:analysis*; D002110:Caffeine / Q000032:analysis*; D018130:Diamond / Q000737:chemistry; D004563:Electrochemistry / Q000295:instrumentation / Q000379:methods*; D004566:Electrodes; D057230:Limit of Detection; D010084:Oxidation-Reduction
chemical_list: D002110:Caffeine; D018130:Diamond