Analysis of the Aerial Parts of Verbena officinalis L. by Micellar Electrokinetic Capillary Chromatography

A micellar electrokinetic capillary chromatography (MECC) method was developed for the qualitative and quantitative determination of five marker compounds (iridoid glycosides, flavonoids and phenylethanoids) in Verbena officinalis. Optimum separation was achieved using a 50 mM sodium borate solution (pH 9.3), containing 50 mM sodium dodecylsulfate (SDS) as surfactant, at an applied voltage of 25 kV and a temperature of 30 °C, respectively. Because of their different absorption maxima, the compounds were detected either at 205 or 235 nm. Calibration data confirmed linearity of the detector response within the concentration range injected (R² from 0.997 to 0.999), and revealed detection limits ranging from 5.0 g mL^–1 (verbascoside) to 13.6 g mL^–1 (hastatoside). The five markers were readily assignable in several samples of Verbena.