title: The use of capillary electrophoresis with contactless conductivity detection for sensitive determination of stevioside and rebaudioside A in foods and beverages.
abstract: Two electrophoretic methods with contactless conductivity detection have been developed for determination of the content of rebaudioside A and stevioside in samples of sweeteners and beverages prepared from extracts of the plant Stevia rebaudiana Bertoni. The total content of rebaudioside A and stevioside can be determined in a fused silica capillary with an inner diameter of 10μm and total length of 31.5cm in optimised background electrolyte with the composition 170mM H3BO3/LiOH (pH 9.0). The combined peak of the two glucosides is characterised by a migration time of 54s, which completely separates it from EOF. INST coating solution in an amount of 0.5% v/v, which effectively suppresses the electroosmotic flow, was added to the background electrolyte for mutual separation of rebaudioside A and stevioside. The CE method with suppression of EOF is characterised by complete separation of rebaudioside A and stevioside, LOD is 0.3mg/L (0.1μM).
authors.affiliation: Charles University, Third Faculty of Medicine, Department of Biochemistry, Cell and Molecular Biology, Ruská 87, 100 00 Prague 10, Czech Republic.
authors.forename: Václav
authors.initials: V
authors.lastname: Pavlíček
authors.affiliation: Charles University, Third Faculty of Medicine, Department of Biochemistry, Cell and Molecular Biology, Ruská 87, 100 00 Prague 10, Czech Republic. Electronic address: petr.tuma@lf3.cuni.cz.
authors.forename: Petr
authors.initials: P
authors.lastname: Tůma
mesh_terms: D001628:Beverages / Q000032:analysis*; D045786:Diterpenes, Kaurane / Q000032:analysis*; D019075:Electrophoresis, Capillary / Q000379:methods*; D005504:Food Analysis / Q000379:methods*; D005960:Glucosides / Q000032:analysis*; D036625:Stevia / Q000737:chemistry; D013549:Sweetening Agents / Q000032:analysis*
chemical_list: D045786:Diterpenes, Kaurane; D005960:Glucosides; D013549:Sweetening Agents; C012043:stevioside; C025474:rebaudioside A
keywords: Capillary electrophoresis; Contactless conductivity detection; Food analysis; High-speed analysis; Rebaudioside A; Stevioside