title: Electrochemical evaluation and adsorptive stripping voltammetric determination of capsaicin or dihydrocapsaicin on a disposable pencil graphite electrode.
abstract: Capsaicin and dihydrocapsaicin are the two most abundant capsaicinoids in peppers, which are responsible for about 90% of the spiciness. A detailed study of the electrochemical properties of these compounds at pencil graphite (PG) electrode was carried out in the pH range 1.0-12.0 in aqueous solutions. The compounds underwent irreversible oxidation at PG electrode, which was an adsorption-controlled process with two protons and two electrons. The voltammetric data indicated that their oxidation proceeded via an ECE mechanism. Using the square-wave adsorptive stripping voltammetry with accumulation at a fixed potential of -0.1V for 120s, both of them yielded a well-defined voltammetric response at +0.31V (vs. Ag/AgCl) in Britton-Robinson buffer, pH 9.0. Capsaicin and dihydrocapsaicin could be determined with detection limits of 1.12 ng mL(-1) (3.7×10(-9)M) and 0.28 ng mL(-1) (9.1×10(-10)M), respectively. The practical applicability of this methodology was tested in commercial Turkish pepper products. The concentration of total capsaicinoids was determined using capsaicin as standard.
authors.affiliation: Yüzüncü Yıl University, Faculty of Science, Department of Analytical Chemistry, 65080 Van, Turkey.
authors.forename: Yavuz
authors.initials: Y
authors.lastname: Yardım
authors.forename: Zühre
authors.initials: Z
authors.lastname: Sentürk
mesh_terms: D000327:Adsorption; D002211:Capsaicin / Q000031:analogs & derivatives* / Q000032:analysis* / Q000737:chemistry; D002212:Capsicum / Q000737:chemistry*; D004566:Electrodes; D005504:Food Analysis / Q000379:methods*; D006108:Graphite / Q000737:chemistry*; D028321:Plant Preparations / Q000737:chemistry; D012639:Seeds / Q000737:chemistry
chemical_list: D028321:Plant Preparations; D006108:Graphite; D002211:Capsaicin; C012906:dihydrocapsaicin