Analysis of Quercetin and Kaempferol in an Alcoholic Extract of Convolvulus pilosellifolius using HPLC

A simple, rapid, and sensitive high-performance liquid chromatography (HPLC) method was developed and validated for identification and determination of flavonoids in Convolvulus pilosellifolius. The chromatographic separation was achieved in less than 6min using C18 column (150x4.6mm, 3 mu m) with isocratic mixture of methanol and water containing 0.1 percent v/v formic acid in the ration of 80:20 at 258nm with a flow rate of 0.4mL/min. The method was validated in the linear calibration curve ranged between 1 and 300 mu g/mL with detection limits of 0.39 and 0.26 mu g/mL and quantification limits of 1.20 and 0.79 mu g/mL for quercetin and kaempferol, respectively. Good repeatability of the method were achieved at percent relative standard deviation (RSD < 2.18 percent) with respect to inter- and intraday repeatability. Recovery values were found to be in the range of 98.2-100.2 percent, indicating high accuracy of the method. The maximum flavonoid contents were 1.07 and 1.54 percent for quercetin and kaempferol, respectively.