毛细管电泳法测定紫草中的紫草素

Determination of Shikonin in Arnebia euchroma (Royle) Johnst by Capillary Electrophoresis

建立了毛细管电泳高频电导法测定紫草药材中左旋紫草素含量的分析方法.以融硅毛细管（150 μm×70 cm）为分离柱,研究了缓冲液的种类、浓度、添加剂种类与添加量、分离电压和进样量等因素对分离和检测的影响,优化选择1.0 mmol/L H3BO3 ＋ 3.0 mmol/L 三乙胺缓冲液为电泳介质,分离电压18.0 kV,可实现分离检测.在优化条件下左旋紫草素线性范围为10.0～250 mg/L;线性相关系数为0.9962;检出限为5.0 mg/L（S/N=3）.2批样品不同浓度添加水平的日内和日间RSD均小于4%,两批药材的加标回收率分别为93.9%～97.4%和 93.1%～101% .该方法简便、快速、灵敏度高,可以用于紫草药材的质量控制.

A method for the determination of Shikonin in Amebia euchroma （Royle） Johnst in two different batches by capillary electrophoresis with high frequency conductivity detection （contacfless conductivity detection） was established. The electrophoretic parameters, such as the variety and concentration of buffer solution, separation voltage etc. were studied. Shikonin in the samples was separated and detected in buffer of 1.0 mmol/L boracic acid ＋ 3.0 mmol/L triethylamine at 18.0 kV of constant voltage. The linear relationship ranged from 10.0 to 250 mg/L （ r = 0.9962）, the limit of detection （ LOD）.,reached 5.0 mg/L （ S/N = 3 ）. The RSDs for both intra-day and inter-day were less than 4% and recoveries were 93.9% - 97.4% and 93. 1% -101% suppository respectively at various spiked levels. This study provides a useful method for the determination of Shikonin in Arnebia euchroma （Royle） Johnst. It can be used for the quality control of products due to its simplicity, rapidity and sensitivity.