Development and Application of a CE Method for Quantification of Phenolic Compounds in Extracts from Buckwheat Herb and in Semi-Solid Formulations Containing the Extracts

Abstract

Because of the growing interest in plant-derived substances for medical and cosmetic applications, appropriate analytical methods must be developed to ensure the quality of herbal extracts. This paper describes a CE method for the quantification of phenolic compounds in extracts from buckwheat herb. The optimum analytical conditions (60 mM borate buffer, pH 10.0, injection time 10 s) were obtained by variation of injection time, the pH and molarity of the running buffer. Comparison with a previously developed HPLC method showed that the new CE method is comparable in terms of precision, linearity, and limit of detection. It is also much faster and less expensive than the HPLC method. Application of the CE method to different extracts showed that the extracts are rather stable to high temperature but very sensitive to high humidity. It is demonstrated that the CE method is also suitable for determination of rutin in buckwheat extracts incorporated into two different semi-solid formulations.