| Autor: |
Custy F. Fernandes, George J. Flick |
| Rok vydání: |
1998 |
| Předmět: |
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| DOI: |
10.1016/s0167-4501(98)80023-x |
| Popis: |
Publisher Summary The capillary electrophoresis methodology combines column chromatographic and gel electrophoretic techniques. The basic electrophoretic principle given in this chapter states that: suppose a sample (e.g., two cationic analytes) is subjected to capillary electrophoretic separation. The two cationic analytes are loaded at the anode and an electrical voltage (V) is applied across the fused silica capillary of total length (L t ). Both analytes will migrate from the anode to the cathode, through the detector. The analyte migration time (t a ) is the interval between the electrophoretic initiation and detection. The analyte migration distance is the effective length (L a ) for on-capillary detection. The electrophoretic mobility (μ ep ) rather than the electrophoretic velocity is preferred, because it facilitates comparison between electropherograms. The zeta potential (Z) is a result of the electrical double layer. The electrical double layer develops between the internal charge on the capillary wall and the charged carder electrolyte. The internal surface of a fused silica capillary is anionic due to the ionization and/or adsorption of cations. The ionization (major contribution) of the silanol groups (SiO) and adsorption (minor contribution) of cations is responsible for the anionic surface. The cations in the carder electrolyte buildup and equilibrate the anionic surface. The electrical double layer generates a potential difference near the capillary wall and is termed “zeta potential.” |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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