高效液相色谱-电化学检测法测定金荞麦饮片中表儿茶素的含量

目的:建立可测定金荞麦饮片中表儿茶素含量的高效液相色谱-电化学检测法。方法:采用DiamonsilC₁₈(4.6 mm×250 mm,5μm)柱,流动相甲醇-0.1 mol.L^-1磷酸盐缓冲液(1∶3,pH 2.5),流速1.0 mL.min^-1,柱温35℃,参比电极ISAAC(in-situ silver/silver chloride),工作电极玻碳电极,检测电位+600 mV。结果:表儿茶素的线性范围为0.004 875～1.56μg,r=0.999 9;平均回收率为100.7%,RSD 1.9%(n=5)。9批不同市售来源的金荞麦饮片中表儿茶素的含量存在差异。结论:该方法重复性好,可以用来测定金荞麦饮片中表儿茶素的含量。

Determination of epicatechin in Rhizoma Fagopyri Dibotoryis by HPLC-ECD

OBJECTIVE: To establish a quantitative method of determination of epicatechin in Rhizoma fagopyri dibotoryis by HPLC-electrochemical detection. METHOD: The sample was separated on a column of Diamonsil C18 (4.6 mm x 250 mm, 5 microm) which was eluted with methanol-0.1 mol x L(-1) phosphate buffer (1:3, pH 2.5), the flow rate was 1.0 mL x min(-1), the column temperature was 35 degrees C, the reference electrode was ISAAC (in-situ silver/silver chloride), the work electrode was glassy carbon, the applied potential was + 600 mV. RESULT: The linear range of epicatechin was 0.004 875-1.56 microg, r = 0.999 9. The average recovery was 100.7% with RSD 1.9% (n = 5). The content of epicatechin was different in nine samples purchased. CONCLUSION: The method is good reproducible and can be used to determine epicatechin in Rhizoma fagopyri dibotoryis.