On-line sample stacking for the analysis of glycyrrhiza flavonoids by anion selective exhaustive injection-sweeping micellar electrokinetic chromatography
阴离子耗尽进样胶束扫集毛细管电动色谱法在线富集测定甘草黄酮类化合物

An on-line preconcentration technique which coupled anion selective exhaustive injection (ASEI)-sweeping technology with micellar electrokinetic chromatography (MEKC) was used to analyze three glycyrrhiza flavonoids (isoliquiritigenin, liquiritigenin and liquiritin) in medicine. The separation conditions were optimized in conventional MEKC. The sample matrix, injection time of water and injection time of sample were found to be the predominant influences on the glycyrrhiza flavonoids stacking. Under optimal conditions, the detection sensitivities were improved by 110, 120, 300 times for isoliquiritigenin, liquiritigenin and liquiritin, respectively. The limits of detection (LODs) were 0.015, 0.014, 0.011mg/L for isoliquiritigenin, liquiritigenin and liquiritin, respectively. The recoveries were ranged in 90.6%~107% and relative standard deviations (RSDs) were less than 4.5%(n=3). This method was successfully applied for the detection of isoliquiritigenin, liquiritigenin and liquiritin in real samples.