Simultaneous Determination of Quercetin, Rutin, Naringin, and Naringenin in Different Fruits by Capillary Zone Electrophoresis

A fast and reliable capillary zone electrophoretic (CZE) method has been developed for the simultaneous determination of four fruit flavonoids using photodiode array (PDA) detector. The effects of CE parameters including concentration and pH of the running buffer, voltage, and injection time were optimized. Under the optimized conditions, all flavonoids were well determined in a 10 mM borate buffer of pH 8.5 within 10 min at an applied voltage of 25 kV. Naringin, naringenin, and quercetin were found to have linear response in the range of 3.12–200 μg/mL whereas rutin’s response was linear from 6.25 to 200 μg/mL. LOD was found to be 0.406, 0.314, 0.582, and 0.333 μg/mL and LOQ 1.355, 1.046, 1.941, and 1.11, respectively. Relative standard deviations (RSD) were found to be less than 3 % for both migration time and peak height which shows long-term stability and good reproducibility of the developed method. The method was successfully applied for the simultaneous determination of flavonoids from various fruit juice samples.