Determination of bioactive constituents in Flos Sophorae Immaturus and Cortex Fraxini by capillary electrophoresis in combination with far infrared-assisted solvent extraction

A method based on far infrared-assisted solvent extraction (FIASE) and capillary electrophoresis–amperometric detection (CE–AD) has developed for the rapid determination of rutin and quercetin in Flos Sophorae Immaturus and esculin and esculetin in Cortex Fraxini. The effects of the irradiation time and the voltage applied on the infrared generator were investigated to acquire the optimum extraction conditions. It was demonstrated that far IR radiation substantially enhanced the extraction efficiency and the extraction time was significantly reduced from 3 h for conventional hot solvent extraction to 6 min for FIASE. The obtained extracts were subsequently analysed by CE–AD. The detection electrode was a 300-μm-diameter carbon disc electrode at a detection potential of +0.90 V (vs. saturated calomel electrode). The relation between peak current and analyte concentration was linear over about three orders of magnitude. The proposed method has been applied to determine the bioactive constituents in real samples.