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Measurement of Stevioside by Square‐Wave Polarography
Author(s) -
KomorskyLovrić Šebojka,
Novak Ivana,
Novak Bruno
Publication year - 2010
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/elan.201000130
Subject(s) - stevioside , steviol , stevia rebaudiana , polarography , chemistry , calibration curve , chromatography , square wave , glycoside , electrolyte , analytical chemistry (journal) , inorganic chemistry , organic chemistry , electrode , food science , voltage , detection limit , electrical engineering , medicine , alternative medicine , pathology , engineering
Steviol glycosides are electroactive compounds and can be detected by mercury electrode. The maxima of square‐wave polarograms of steviol and stevioside appear at −1.3 V vs. Ag/AgCl in 1 M NaCl at approximately pH 11. The responses are quasireversible and probably caused by electroreduction of carboxyl, or ester groups, respectively. The net peak current is linearly proportional to steviol concentration between 1×10 −6 mol/L and 3.5×10 −5 mol/L. This calibration plot can be used for the determination of the concentration of stevioside in extracts of stevia ( Stevia rebaudiana Bertoni ) leaves. The proposed method is applicable for routine analysis of stevioside in commercial products.