Simultaneous determination of quercetin and luteolin in mate and white tea samples

The chemical structures of quercetin and luteolin are quite similar; as a result, their oxidation peaks potential are close and interfere each other. To solve this problem, in this study, the simultaneous determination method of quercetin and luteolin has been developed on glassy carbon electrode (GCE) by using differential pulse voltammetry (DPV). 75% methanol (hydro-alcoholic) support electrolyte was used for this purpose. The peak potential difference between the quercetin and luteolin was at about 110 mV which was useful for the simultaneous electrochemical analysis of both species.