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Published on: November 12, 2016
System zones in capillary zone electrophoresis
J L Beckers1, P Gebauer, P Bocek
1Eindhoven University of Technology, Department of Chemistry (SPO), The Netherlands.
System zones (SZs) are inherent to capillary zone electrophoresis (CZE) and influenced by background electrolyte (BGE) composition. Understanding SZ migration is key to avoiding analytical interferences in CZE separations.
Area of Science:
- Analytical Chemistry
- Separation Science
- Electrophoresis
Background:
- System zones (SZs) are an inherent feature of capillary zone electrophoresis (CZE).
- Their formation and migration are primarily dependent on background electrolyte (BGE) composition.
- SZs can be stationary or migrating, influenced by BGE properties and sample injection.
Purpose of the Study:
- To provide an overview of system zones (SZs) in capillary zone electrophoresis (CZE).
- To elucidate the effects of SZs on analyte zone migration.
- To discuss practical strategies for managing SZs in CZE analysis.
Main Methods:
- Theoretical analysis of SZ formation and migration mechanisms.
- Characterization of SZ mobility based on BGE composition.
- Exemplification of SZ effects on analyte peaks using experimental observations.
Main Results:
- SZs are analyte-free zones with BGE-like composition, differing in component concentrations.
- Migrating SZs can be detected as system peaks/dips when BGE components are visible.
- SZs can cause peak broadening, irregular shapes, and other disturbances in analyte zones.
Conclusions:
- SZs formation and behavior are predictable based on BGE characteristics.
- Understanding SZ mobility and the 'unsafe region' is crucial for method development.
- Selecting operational conditions to avoid the unsafe region ensures reliable CZE analysis.
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