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[16] Capillary electrophoresis of oligosaccharides

1994; Academic Press; Linguagem: Inglês

10.1016/0076-6879(94)30018-6

1557-7988

Robert J. Linhardt,

Electrowetting and Microfluidic Technologies

This chapter focuses on the analysis of both underivatized and derivatized oligosaccharides by capillary zone electrophoresis (CZE) in unmodified, unfilled fused silica capillaries. Capillary zone electrophoresis relies on simple instrumentation that includes a high-voltage supply, a capillary column, and a detector. The capillary column invariably carries a negative charge on its inner surface because the silanol groups of the uncoated capillary ionize above pH 3. The addition of sodium dodecyl sulfate (SDS) to the electrolyte buffer results in partitioning of the analyte between the micelle and the surrounding aqueous phase. Separation is accomplished through differential migration of the phases. There are a number of different methods that can be used to inject a sample into the capillary column for analysis. Gravity injection is an unbiased method of introducing both charged and neutral analytes. Typically, gravity injection that relies on capillary action is used. A high voltage, typically ranging from 10 to 20 kV, is used in CZE. The length of time required for each analysis is usually from 2 to 90 min, depending on capillary length, voltage, buffer, and the net charge of the sample.