毛细管电泳法测定大豆籽粒中异黄酮含量

DETERMINATION OF ISOFLAVONES CONTENT IN SOYBEAN SEEDS BY CAPILLARY ELECTROPHORESIS

大豆异黄酮是一种具有重要生理活性的物质.本研究采用未涂层熔融石英毛细管柱(50 cm×75 μm,有效长度为42 cm),对电泳条件进行优化,拟建立快速检测大豆籽粒中异黄酮含量的毛细管电泳法.结果表明优化的最佳电泳条件为:以5%甲醇与95%硼砂(40 mmol/L,pH=10.0)溶液为电泳缓冲液,压力进样20 s,温度25℃,分离电压16.5 kV,检测波长为254 nm.在此条件下,大豆籽粒中6种异黄酮组分可在21 min内完全分离并具有良好的线性关系;6种异黄酮组分的峰面积和保留时间的相对标准偏差(RSD)分别在0.5%～2.4%之间和1.8%～3.8%之间,加样回收率在97.2%～103.3%之间,以鹰嘴豆芽素A作为内标可提高电泳的重现性.表明建立的方法灵敏、准确、经济、重现性好,适用于大豆籽粒中异黄酮含量的测定.

Isoflavones is an important biofunctional substance.Capillary electrophoresis with a uncoated fused-silica capillary tube(50 cm 75 μm.i.d,effective length 42 cm) was used to optimize soybean isoflavones analysis.The optimum electrophoresis conditions were as follows: 40 mmol/L sodium borate containing 5% methanol as the running buffer(pH=10.0),electrophoretic voltage being 16.5 kV,temperature being 25 OC and detecting wavelength being 254 nm.Under the optimum conditions,6 kinds of isoflavones could be clearly separated within 21 minutes.The corrected peak areas of isoflavones increased linearly with components of isoflavones.RSD of the peak area and holding time of 6 isoflavones were 0.5%~2.4% and 1.8%~3.8%,respectively,and the recoveries were ranged from 97.2% to 103.3%.The biochanin was used as an internal standard and could increase the recurrence of experiment.The newly-built method is sensitive,simple,economical and well recurrent,and can be used for the determination of isoflavones components in soybean seed.