微流蒸发光散射检测器与毛细管液相色谱的联用及其在银杏叶提取物分析中的应用

将微流蒸发光散射检测器( μELSD)与毛细管液相色谱(cLC)联用,应用于中药银杏叶提取物及其分散片制剂的分离检测领域。首先对 μELSD仪器参数进行优化。通过调节漂移管温度与载气流量,提高了分析物的响应,并减小了噪声。然后,搭建了cLC-μELSD分离检测平台,其相对常规LC可大大减小实验试剂消耗。流动相A为0.05%(体积分数,下同)三氟乙酸(TFA)水溶液,流动相B为含0.05% TFA的甲醇溶液。最优的洗脱梯度条件为:0~10 min,5%B~25%B;10~25 min,25%B~38%B;25~35 min,38%B;35~40 min,38%B~42%B;40~55 min,42%B~50%B。银杏叶提取物和复杂中药制剂银杏叶提取物分散片都得到了较好的分离,并在其中鉴定到紫外波段几乎无吸收的重要内酯类活性成分白果内酯以及银杏内酯A、B和C。测定了不同厂家银杏叶提取物中萜类内酯洗脱时间的相对标准偏差,结果均不大于2.42%,表明该体系在目标物的分析上具有良好的重现性。实验证明所建立的cLC-ELSD体系在复杂中药体系的分离检测中有良好的应用性。

Microfluidic evaporative light scattering detector coupled with capillary liquid chromatography and its application to Ginkgo biloba extract analysis

A novel separation system of microfluidic evaporative light scattering detector( μELSD) coupled with capillary liquid chromatography (cLC) was built and applied to the separation and detection of herbal medicine Ginkgo biloba extract and its disperse tablet formulation. Compared with the traditional HPLC, this μELSD-cLC system consumed much less sample and solvent. Some key parameters were optimized. It was found that the higher the evaporization temperature of the drift tube, the higher S/N could be achieved. The mobile phase A was 0.05% (v/v) trifluoroacetic acid (TFA), and the mobile phase B was methanol containing 0.05% (v/v) TFA. The optimized gradient conditions were as follows: 0-10 min, 5%B-25%B; 10-25 min, 25%B-38%B; 25-35 min, 38%B; 35-40 min, 38%B-42%B; 40-55 min, 42%B-50%B. The complex herbal medicine Ginkgo biloba extract and its disperse tablet formulation were successfully separated. Four main therapeutic components (bilobalide and ginkgolide A, B, C) were finally separated and determined, which were terpene lactones with pretty weak UV absorption. The RSDs of the detected terpene lactones from different manufacturers were all no more than 2.42%, which proved this platform’s good analysis repeatability. The results showed the applicability of the platform to the analysis of complex traditional Chinese medicines.