毛细管电泳-电化学检测法测定淮山中三种植物甾醇含量

Determination of Three Phytosterols in Yam by Capillary Electrophoresis With Electrochemical Detection

以淮山为试材,采用毛细管电泳-电化学检测(CE-ED)方法测定淮山中3种植物甾醇(麦角甾醇、胆甾醇、β-谷甾醇)的含量,考察了检测电位、运行缓冲液浓度和pH、分离电压及进样时间等对检测效果的影响。结果表明:在优化的条件下,对0.5mg·L^(-1)麦角甾醇、胆甾醇、β-谷甾醇混合标准溶液连续6次进行测定在10min内实现了分离,线性范围分别为0.1~1 500、0.1~1 000、0.1~1 200μg·L^(-1),检出限分别为0.03、0.04、0.03μg·L^(-1),峰电流的相对标准偏差(RSD)分别为1.5%、1.7%、1.6%,迁移时间RSD分别为0.6%、0.7%、0.6%。该方法已用于淮山样品中胆甾醇、麦角甾醇和β-谷甾醇的测定,加标回收率在97.6%~100.3%,相对标准偏差(RSD)≤2.3%。

Taking yam as test material,a method of capillary electrophoresis coupled with electrochemical detection（CEED）was adopted for the determination of three phytosterol content（ergosterol,cholesterol,β-sitosterol）in yam.The effects of detection potential,concentration and pH of running buffer,separation voltage and injection time on the detection were investigated.The results showed that under the optimum conditions,agood baseline separation and highly sensitive detection were achieved in 10 minutes good linear relationship between peak currents and ergosterol,cholesterol and β-sitosterol concentration ranging from 0.1^-1 500μg·L^-1,0.1^-1 000μg·L^-1,0.1^-1 200μg·L^-1,with the detection limits（S/N=3）of 0.03μg·L^-1,0.04μg·L^-1,0.03μg·L^-1,respectively,the relative standard deviations（RSD）of peak currents were 1.5%,1.7%,1.6%,RSD of the migration time were 0.6%,0.7%,0.6%.The method was successfully applied to the assay of cholesterol,ergosterol and β-sitosterol in samples of yam.The spiked recoveries were in the range of 97.6%^-100.3%,with relative standard deviations less than 2.3%.