高效毛细管电泳方法同时测定茶叶中多种水溶性维生素

建立了毛细管电泳法同时分离检测多种水溶性维生素的方法,在柱温25℃、电压20 kV、20 mmol/LpH8.8磷酸二氢钾-硼砂缓冲液的电泳条件下,10 min内实现了7种水溶性维生素(VB1、VB12、VB2、VB6、Vc、烟酸和叶酸)的良好分离。比较了水浴萃取、超声波萃取以及SPEC18柱萃取对茶样中维生素分离效果的影响,结果显示SPEC18柱具有较好的纯化和富集作用。利用上述的毛细管电泳法对茶树顶芽和叶片中7种水溶性维生素进行了检测,其迁移时间重现性为0.155 7%~0.166 4%,峰面积重现性为1.080%~3.466%,回收率为96.3%~103.9%。结果还显示茶树顶芽中的水溶性维生素含量最高。

Simultaneous Determination of Water-soluble Vitamins in Tea by Capillary Electrophoresis

A method was applied to determine several water-soluble vitamins by capillary electrophoresis.Separation of VB1,VB12,VB2,VB6,Vc,nicotinic folic and folic acid were obtained with capillary electrophoresis with 20 mmol/L borate buffer solution(pH 8.8),temperature 25 ℃ and voltage 20 kV in 10 min.The extracting effects of water,ultrasonic and SPE C18 cartridge on the separation of water-soluble vitamins in tea leaf were compared.The result showed that the vitamins in tea leaf were purified and enriched by means of C18 cartridge.Seven water-soluble vitamins in tea leaf were tested by capillary electrophoresis.The 0.155 7%～0.166 4% of retention time(RSD),1.080%～3.466% of peak area(RSD),96.3%～103.9% of recovery and 0.03 μg/ml of detection limit were obtained.The result showed that the sprout of tea plant rich in water-soluble vitamins.