生物碱样品中有效成分的CZE法分离与测定

Separation and Determination of Effective Compounds in Alkaloidal Samples by Capillary Zone Electrophoresis

建立了一种简单的同时分离测定生物碱样品中咖啡因、可可碱和茶碱3种有效成分的区带毛细管电泳法。采用未涂层石英毛细管(75μm i.d.×60 cm,有效长度50 cm),以20 mmol.L-1硼砂-4 mmol.L-1β-CD(pH 9.0)为运行缓冲液,压力(0.5 psi)进样5 s,运行电压16 kV,检测波长273 nm,温度25℃。在优化的实验条件下,3种生物碱的电泳谱图峰面积与其质量浓度在0.036～0.288 g.L-1呈良好线性关系(r≥0.998 4);方法的精密度、重复性和稳定性良好,其峰面积的RSD均不大于3.2%,其检出限均不大于2.7mg.L-1;加标回收率为97%～104%。该方法简单、快速、试剂消耗少,可用于生物碱样品中咖啡因、可可碱和茶碱的分离与测定。

A capillary zone electrophoresis（CZE） method was established for the separation and determination of three effective compounds such as caffeine,theobromine and theophylline in alkaloidal samples.The sample was separated on an uncoated silica capillary（75 μm i.d.×60 cm,effective length：50 cm） using pH 9.0 20 mmol·L-1 borate containing 4 mmol·L-1 beta-cyclodextrin（β-CD） as running buffer.The pressure of injection was set at 0.5 psi and the time was set 5 s.The detection wavelength was 273 nm.A voltage of 16 kV was applied at 25 ℃.Under the optimal conditions,good linear relationships were observed between peak areas and alkaloidal concentrations in the range of 0.036-0.288 g·L-1,with correlation coefficients not less than 0.998 4.The RSDs of the peak area were not more than 3.2%.The limits of detection（LODs） were not more than 2.7 mg·L-1.The average recoveries were in the range of 97%-104%.This method is simple,quick and less reagent-consuming,and is suitable for the separation and determination of the three alkaloids in real samples.