毛细管电泳分析中的富集技术及其应用

毛细管电泳(CE)具有分析速度快、分离效率高、样品消耗少、成本低廉等优点,已被应用于无机离子、有机小分子、蛋白质、核酸及细胞等的分析中。CE中最常用的检测方式是紫外检测(UV),但由于常规进样样品体积小、检测光程短,CE-UV的灵敏度往往不能满足复杂样品中痕量物质直接分析的要求。CE中的在柱富集技术包括堆积、动态pH界面、吹扫和瞬间等速电泳等,可在很大程度上提高CE-UV的检测灵敏度;另外,固相和液相微萃取技术及其与在柱富集技术相结合应用在CE中也能净化样品基质,进一步提高富集倍数,改善分析灵敏度,从而拓宽了CE-UV在复杂样品分析中的应用范围。

Concentration techniques in capillary electrophoresis analysis and their applications

Capillary electrophoresis (CE), as a modern analytical technique, has been successfully applied in the analysis of metal ions, organics, proteins, nucleic acids and cells, due to its short analysis time, high separation efficiency, low sample consumption and low cost. Since most commercial CE instruments are equipped with ultraviolet detectors (UV), the application of CE-UV with low sensitivity owing to limited optical pathway of on-capillary photometry and the small sample injection volume, is strictly limited in real sample analysis. On-column preconcentration technique is an efficient approach to greatly improve the sensitivity of CE-UV, which can be achieved by merely adjusting the parameters, without any modification of the instrument. At present, stacking, dynamic pH junction, sweeping and transient isotachophoresis are the commonly used on-column preconcentration techniques in CE analysis, and have been extensively utilized in food science, environmental science and biomedicine fields. On the other hand, for real sample analysis, proper sample pretreatment is often necessary prior to instrumental analysis, aiming to remove sample matrix and enrich target analytes simultaneously. With the development tendency of economy, miniaturization and automation in modern analytical methods, green and miniaturized sample pretreatment techniques such as solid phase microextraction (SPME) and liquid phase microextraction (LPME) have been developed rapidly in recent decades. The combination of miniaturized sample pretreatment techniques and CE on-column preconcentration techniques can provide a promising method for the determination of trace analytes in complicated real samples.