LVSS-CE法测定独一味中黄酮类成分研究

Optimization of Large Volume Sample Stacking for Analysis of Flavonoids in Lamiophlomis rotata by Capillary Electrophoresis

[目的]建立大体积进样堆积-毛细管电泳（LVSS-CE）法,富集并测定独一味全草中槲皮素、木犀草素、芹菜素和木犀草素-7-O-葡萄糖苷的含量。[方法]分离条件为：背景电解质为30 mmol/L硼酸盐溶液（pH 9.0）,含8%（V/V）乙腈,分离电压20 kV,检测波长为210nm。进样堆积过程为：流体动力进样5 000 Pa×250 s,施加-25 kV至基质完全排出,20 kV进行分离。[结果]木犀草素-7-O-葡萄糖苷、芹菜素、木犀草素和槲皮素的堆积因子分别达到33、31、50和51,最低检测限分别为10.0、4.5、2.5、2.5μg/L。与常规电泳流体动力进样5 000 Pa×3 s相比,该法提高检测灵敏度300~800倍。[结论]该法简单易行,结果准确度高,精密度好,可用于检测药物中低含量的黄酮类化合物。

[Objective] A capillary electrophoresis（CE） method with large volume sample stacking（LVSS） was developed for simultaneous analysis of four flavonoids luteolin-7-O-glucoside,apigenin,luteolin and quercetin.[Method] Optimum separation was obtained with 30 mmol/L borate containing 8% acetonitrile（V/V）,pH 9.0,by applying a voltage of 20 kV at 20 ℃.Sample solution was injected for 250 s at a pressure of 5 000 Pa,then a voltage of-25 kV was applied to pump out the sample matrix and pump in BGE by electroosmotic flow（EOF）,finally the voltage was switched to positive（＋20 kV） to perform the separation when the produced current reached 96%-99% of its normal value.[Result] The limits of detection were 10.0,4.5,2.5 and 2.5 μg/L for luteolin-7-O-glucoside,apigenin,luteolin and quercetin respectively,and the detection sensitivity was improved about 300-800 fold with those obtained from 5 s at hydrodynamic injection.[Conclusion] The method was applied to determine four flavonoids in Lamiophlomis rotata successfully.The results demonstrated that it was an easy-to-use method for the analysis of minor flavonoids.