Chen Gang, Zhang Luyan, Yang Pengyuan
Department of Chemistry, Fudan University, Shanghai 200032, China.
Anal Sci. 2005 Oct;21(10):1161-5. doi: 10.2116/analsci.21.1161.
Capillary electrophoresis with electrochemical detection has been employed for the separation and determination of the three active constituents (paeonol, benzoyloxypaeoniflorin, and oxypaeoniflorin) in traditional Chinese medicine, Moutan Cortex (root cortex of Paeonia suffruticosa Andrews). The effects of several important factors, such as the concentration of running buffer, the separation voltage, the injection time, and the detection potential, were investigated to determine the optimum conditions. The detection electrode was a 300 microm diameter carbon-disc electrode at a working potential of +0.90 V (versus SCE). The three analytes could be well separated within 7 min in a 40 cm length fused-silica capillary at a separation voltage of 12 kV in a 50 mM borate buffer (pH 9.2). The relation between the peak current and the analyte concentration was linear over 3 orders of magnitude with detection limits (S/N = 3) ranging from 0.4 to 0.7 microM for all analytes. The proposed method has been successfully applied to the determination of paeonol, benzoyloxypaeoniflorin, and oxypaeoniflorin in real plant samples with satisfactory assay results.
采用毛细管电泳-电化学检测法对中药牡丹皮（牡丹根皮）中的三种活性成分（丹皮酚、苯甲酰芍药苷和芍药苷）进行分离和测定。研究了运行缓冲液浓度、分离电压、进样时间和检测电位等几个重要因素的影响，以确定最佳条件。检测电极是直径为300微米的碳圆盘电极，工作电位为+0.90 V（相对于饱和甘汞电极）。在50 mM硼酸盐缓冲液（pH 9.2）中，于12 kV的分离电压下，在40 cm长的熔融石英毛细管中，三种分析物可在7分钟内得到良好分离。峰电流与分析物浓度之间的关系在3个数量级内呈线性，所有分析物的检测限（信噪比=3）为0.4至0.7 microM。该方法已成功应用于实际植物样品中丹皮酚、苯甲酰芍药苷和芍药苷的测定，测定结果令人满意。
