毛细管电泳法检测紫甘蓝色素酰基化基团的成分

Determination of Acylation Groups′ Components of Purple cabbage Pigment by Capillary Electrophoresis

采用毛细管电泳电化学检测法测定了紫甘蓝色素酰基化基团的组分,即分别为芥子酸、阿魏酸、P-香豆酸和咖啡酸。实验优化了4种酸的电泳条件：以直径300μm的碳圆盘电极作为工作电极,检测电位为0.9 V（vs.SCE）,分离电压14 kV,进样6 s,在浓度为60 mmol/L硼砂（pH8.7）运行缓冲液中,上述4种组分能够在10 min内完全分离。4种酸的混合标准溶液7次连续平行进样,重现性良好,峰高的相对标准偏差（RSD）分别为：2.7%,2.4%,1.6%和4.1%。4种酸的峰高与浓度在2-3个数量级范围内线性关系良好,检出限质量浓度分别为：2.5×10^-7,3.0×10^-7,3.2×10^-8和1.0×10^-7g/mL。该方法简单易行,快速灵敏可靠。

The aim of this work was to identify acylation groups of anthocyanins in purple cabbage by capillary zone electrophoresis（CZE） coupled with electrochemical detection（ED）.The effects of the detection potential,pH and concentration of running buffer,separation voltage and injection time on the separation and detection have been examined.The experimental conditions are as follows： 300 μm diameter carbon disk electrode as the working electrode,detection potential 0.9 V（vs.SCE）,separation voltage 14 kV,injection time 6 s,60 mmol / L borax（pH 8.7） as the running buffer.Sinapic acid,ferulic acid,p-coumaric acid and caffeic acid,which are present in the hydrolyzate of red cabbage extracts as acylation groups,were detected within 10 mins.Standard sample were injected 7 times continuously,the relative standard deviation（RSD） on peak height were： 2.7%,2.4%,1.6% and 4.1% for sinapic acid,ferulic acid,coumaric acid and caffeic acid,respectively.The peak heights and concentrations had a good linear relationship within 2～3 magnitude range.The detection limits（S/N=3） were： 2.5×10^-7,3.0×10^-7,3.2×10^-8,1.0×10^-7 g/mL.The CZE-ED is a fast and sensitive detection method to study purple cabbage pigment structure and components.