毛細管電泳技術近年來被積極推廣，因為它有著快速、高分離效率及微量分析的優點。目前中草藥的開發與應用已有明顯的發展，對於中草藥中高含量的醣類，因有較佳的生物活性而被分析探討。本實驗沿續本實驗室研究成果以毛細管電泳電化學偵測法(CE-ECD)為基礎，在不必添加衍生劑的情況下，針對傳統中草藥中的醣類做分離與偵測。改進電化學偵測器之設計，降低偵測極限。冬蟲夏草中甘露醇具有一定的藥效成份，對冬蟲夏草有很大的影響，因此我們使用較一般長度短(20cm)，內徑為20μm的毛細管在鹼性電解液環境下進行分離，除了能縮短分離時間外，更能有效分離偵測出北冬蟲夏草中甘露醇的成份，另一方面也可以來確認北冬蟲夏草中其他的醣類成份，以確保樣品本身的品質穩定。電化學偵測器之改進設計，對北冬蟲夏草中甘露醇和其他可能並存的醣類之移動時間在850秒之內皆可偵測出，除了可降低甘露醇的偵測極限達5.0μM，線性範圍為0.0050~5.00mM，對真實樣品之測定有極大的幫助。 A simple, fast, reliable and reproducible method based on capillary electrophoresis with electrochemical detection (CE-ECD), for the determination of mannitols in Cordyceps militaris was described in this study. However, carbohydrates are in general difficult to separate and detect due to their lack of readily ionizable functional groups and chromophores. Precolumn derivatization is the most widely used means, and most of the methods are based on reductive amination. A copper microelectrode was used as working electrode carbohydrates can be detected directly without derivatization. Moreover, with electrochemical detection, CE–ECD offers high sensitivity and good selectivity for the determination of carbohydrates. Mannitol, glucose, and mannose can be well separated in a 20 cm length, 20μm i.d fused-silica capillary in a 0.050M NaOH with 0.15M KCl aqueous solution. With the improved capillary electrophoresis-amperometric determination in optimized condition of separation and detection, the migration time of mannitol and carbohydrates are within 850 sec determination with linear dynamic range of 5.00mM to 0.05mM and of 0.005mM limit of detection(LOD).
