Analysis of Total Flavonoids in Herbal Drugs Expressed as Quercetin by Reversed Phase-UHPLC Method

Abstract

A rapid and accurate reversed phase-UHPLC method is developed for determination of gallic acid, quercetin and kaempferol in herbal drugs found in herbal product purchased from local market. A reversed phase chromatographic analysis is carried out under isocratic conditions using column Phenomenex, Prodigy, ODS3, 5.0 μm, 100 A, 250 × 4.6 mm (USA). The mobile phase is methanol and 0.5 % phosphoric acid (50:50 v/v). The flow rate is 1.3 mL min-1. The injection volume is 20 µL. The detection wavelength (λ max) is 370 nm using a PDA (photodiode array detector). Linearity of the method is established over the concentration ranges of 240-960 µg mL-1 for quercetin with a retention time about 7.8 minutes. Correlation coefficient is greater than 0.99. The recovery level of quercetin is 99.94 %. The described method is quite suitable for routine analysis of herbal drugs by reversed phase-UHPLC Method. The proposed method is used for routine analysis to estimate the selected polyphenols under study in its pure form as well as in some herbal drugs forms.

Quality control and standardization of Quercetin in herbal medicines by spectroscopic and chromatographic techniques

“…The analysis done on column Phenomenex and methanol and 0.5% phosphoric acid (50:50v/v) as mobile phase with flow rate of 1.3 ml/min. Linearity of the method is established over the concentration range of 240-960 µg/ml for quercetin and retention time were found 7.8 min [46].…”