Rapid Analysis of Alpinetin and Cardamonin in Alpinia katsumadai Hayata Using Short-End Injection Microemulsion Electrokinetic Capillary Chromatography Combined with Microwave-Assisted Extraction

Abstract

A rapid and simple short-end injection microemulsion electrokinetic chromatography (MEEKC) method was developed for the routine analysis of alpinetin and cardamonin in Alpinia katsumadai Hayata in combination with microwave-assisted extraction (MAE). The key parameters affecting separation and extraction were investigated and optimized. The optimal MAE was performed at 800 W for 12 min with 100% ethanol as the extraction solvent, which gave a better extraction efficiency and required a significantly shorter time than conventional heat reflux extraction (HRE) and ultrasonic extraction (USE). When this detection system based on ethyl acetate oil-based MEEKC and short-end injection was applied, the analysis was completed in less than 1.5 min. In the method validation, the relative standard deviations of the migration times and peak areas of the two constituents were 0.74, 1.86% for alpinetin and 0.63, 2.05% for cardamonin, respectively. The recoveries ranged from 94.6 to 105.8%. Compared with previously reported methods, the present method offers a dramatic decrease in overall analysis time, and has the further advantages of easy operation and low running costs.