Petra Ševčíková

Determination of lignans in Schisandra chinensis using micellar electrokinetic capillary chromatography.

Micellar electrokinetic capillary chromatography (MEKC) has been developed as a promising method for the determination of lignans in plant samples. The separation conditions have been optimized with respect to the different parameters including sodium dodecyl sulfate (SDS) and acetonitrile concentration, pH of the background electrolyte, separation voltage, and capillary temperature. The background electrolyte consisting of 40 mM SDS and 35% acetonitrile in 10 mM tetraborate buffer (pH 9.3) was found to be the most suitable electrolyte for this analysis. The applied voltage of 28 kV (positive polarity) and the capillary temperature 25°C gave the best separation of lignans. The interday reproducibility of the peak areas and the migration times was below 2.0%. The results of MEKC analyses were compared with those obtained by capillary electrochromatography (CEC) and reversed‐phase high‐performance liquid chromatography (RP‐HPLC). The possibilities of using this method for the determination of lignans in drug and in serum samples were also tested.

Analysis of artichoke (Cynara cardunculus L.) extract by means of micellar electrokinetic capillary chromatography.

The main constituents of artichoke extract were separated by micellar electrokinetic chromatography (MEKC), using a buffer consisting of 100 mM sodium dodecyl sulfate (SDS) in 20 mM sodium dihydrogen phosphate, 20 mM disodium tetraborate (pH 8.6) as background electrolyte. Optimum separation voltage of 28 kV (positive polarity) and a capillary temperature of 25°C gave the best analysis. The UV detection was performed at 200 nm. The method was successfully used to analyze plant and drug samples as well as for the study of artichoke antioxidant activity. The quantitative MEKC results were in good agreement to those obtained previously by reversed‐phase high‐performance liquid chromatography (RP‐HPLC).