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

建立了一个毛细管胶束电动色谱(MEKC)在线富集阴离子耗尽进样(ASEI)联用扫集(sweeping)技术测定3种甘草黄酮化合物(异甘草素、甘草素和甘草苷)的方法。考察了MEKC的分离条件和富集体系的优化条件,其中样品基质、水塞进入时间、进样时间对目标化合物的富集效果有较大的影响。在优化实验条件下,异甘草素、甘草素和甘草苷的富集倍数分别提高了110、120、300倍,检出限分别为0.015、0.014、0.011mg/L。该方法用于中药制剂中甘草素、异甘草素和甘草苷含量的测定,回收率在90.6%～107%之间,相对标准偏差(RSD)均小于4.5%(n=3)。实验证明,该方法可成功地应用于实际样品中甘草素、异甘草素和甘草苷含量的测定

On-line sample stacking for the analysis of glycyrrhiza flavonoids by anion selective exhaustive injection-sweeping micellar electrokinetic chromatography

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.