目的:采用毛细管区带电泳法测定麻黄及麻杏石甘汤中麻黄碱和伪麻黄碱。方法:电泳缓冲液为50 mmol.L-1硼砂/20 mmol.L-1苏氨酸缓冲溶液(1 mol.L-1NaOH溶液调pH至9.27);紫外检测波长210 nm,分离电压15 kV;以苯巴比妥为内标物,采用压力进样(10 cm×20 s),柱温室温。结果:麻黄碱与伪麻黄碱的线性范围分别为21.3~213,8.4~84 mg.L-1,相关系数分别为0.9996,0.9995,检测限分别为1.45,1.48 mg.L-1,定量限分别为4.81,4.93 mg.L-1。将该法用于麻黄中麻黄碱与伪麻黄碱的含量测定,平均回收率分别为97.5,98.6%。结论:本法操作简便、快速、经济、灵敏度高,麻黄及麻杏石甘汤中麻黄碱及伪麻黄碱可获得满意的分离,可作为麻黄和麻杏石甘汤中麻黄碱和伪麻黄碱的含量测定方法。 Objective: To determine ephedrine and pseudoephedrine in Ephedra and Maxing Shigan Decoction by capillary zone electrophoresis. Methods: The electrophoresis buffer consisted of 50 mmol·L-1 borax / 20 mmol.L-1 threonine buffer solution (pH adjusted to 9.27 with 1 mol·L-1 NaOH solution); the UV detection wavelength was 210 nm and the separation voltage was 15 kV; With phenobarbital as internal standard, using pressure injection (10 cm × 20 s), column temperature room temperature. Results: The linear ranges of ephedrine and pseudoephedrine were 21.3 ~ 213,8.4 ~ 84 mg.L-1, the correlation coefficients were 0.9996,0.9995, the detection limits were 1.45,1.48 mg.L-1, respectively, and the limits of quantification were 4.81 , 4.93 mg.L-1. The method was applied to the determination of ephedrine in ephedrine and pseudoephedrine, the average recoveries were 97.5 and 98.6% respectively. Conclusion: This method is simple, rapid, economical and sensitive. Ephedrine and pseudoephedrine in ephedra and Maxingshigan decoction can be separated satisfactorily, and can be used as a method for the determination of ephedrine and pseudoephedrine in ephedra and Maxingshigan Decoction .