采用高效毛细管电泳法,分别对5个不同产地苦荞中黄酮类化合物进行检测。电泳条件:10 mmol/L Na2B4O7-H3BO3缓冲溶液,pH 9.3,检测波长218 nm,分离电压25 k V。在该条件下,表儿茶素、芦丁、山奈酚和槲皮素4种黄酮类化合物在7 min内得到分离,线性范围分别为0.03~0.54、0.05~0.97、0.03~0.63、0.04~0.90 mg/mL,相关系数为0.992 3~0.998 7,最低检出限分别为5.33×10^-6、1.80×10^-5、2.51×10^-5、1.24×10^-5 mg/mL(RSN=3),平均回收率在95.5%~104.7%之间,相对标准偏差不大于3.66%。结果表明:该方法准确可靠,可用于苦荞中黄酮类化合物的检测。
An efficient high performance capillary electrophoresis(CE) method has been successfully developed for the determination of flavonoids in buckwheat. The running buffer contained 10 mmol/L Na2B4O7-Na H2PO4, at pH 9.3, the detection wavelength was set at 218 nm and a voltage of 25 k V was applied. Under these conditions, four flavonoids, i.e., picatechin, rutin, kaempferd and quercetin, could be fully separated from each other within seven minutes. The linear ranges were 0.03 to 0.54, 0.05 to 0.97, 0.03 to 0.63, and 0.04 to 0.90 mg/mL, respectively, with correlation coefficients between 0.992 3 and 0.998 7 and the limits of detection(LOD) were 5.33 ×10^-6, 1.80 ×10^-5, 2.51 ×10^-5, and 1.24 ×10^-5 mg/mL, respectively(RSN = 3). The average recoveries were between 95.5% and 104.7%, with a relative standard deviation(RSD) less than 3.66%. This method is convenient to operate, accurate, efficient and suitable for the simultaneous detection of flavonoids in buckwheat.