Varjo Sami J O, Ludwig Martin, Belder Detlev, Riekkola Marja-Liisa
Laboratory of Analytical Chemistry, Department of Chemistry, University of Helsinki, Finland.
Electrophoresis. 2004 Jun;25(12):1901-6. doi: 10.1002/elps.200405914.
On-chip capillary electrophoresis with uncoated and polyvinyl alcohol-coated glass channels in aqueous and nonaqueous dimethyl sulfoxide (DMSO) background electrolyte (BGE) solutions was applied in the separation of five amines derivatized with fluorescein-5-isothiocyanate. In aqueous BGE at pH 9.2, baseline separation of the analytes was not achieved on uncoated glass chips, but the separation was clearly improved when the chip channels were coated with polyvinyl alcohol (PVA). Separation was successful in nonaqueous DMSO electrolyte solution containing ammonium acetate and sodium methoxide, on both uncoated and PVA-coated glass microchips. The differences in the pK(a) values of analytes were probably amplified in DMSO, and all five analytes were at least partly dissociated and were separated. Because the viscosity of DMSO is higher than that of water, the migration times were longer in DMSO.
采用未涂层和聚乙烯醇涂层的玻璃通道，在水性和非水性二甲基亚砜（DMSO）背景电解质（BGE）溶液中进行芯片毛细管电泳，用于分离用异硫氰酸荧光素衍生化的五种胺。在pH 9.2的水性BGE中，未涂层玻璃芯片上未实现分析物的基线分离，但当芯片通道用聚乙烯醇（PVA）涂层时，分离效果明显改善。在含有醋酸铵和甲醇钠的非水性DMSO电解质溶液中，未涂层和PVA涂层的玻璃微芯片上均成功实现了分离。分析物pK(a)值的差异在DMSO中可能被放大，所有五种分析物至少部分解离并被分离。由于DMSO的粘度高于水，在DMSO中的迁移时间更长。
