Multivalent weak electrolytes - risky background electrolytes for capillary zone electrophoresis

0162399 - UIACH-O 20020051 RIV DE eng J - Journal Article
Beckers, J. L. - Boček, Petr
Multivalent weak electrolytes - risky background electrolytes for capillary zone electrophoresis.
Electrophoresis. Roč. 23, č. 12 (2002), s. 1942-1946. ISSN 0173-0835. E-ISSN 1522-2683
R&D Projects: GA ČR GA203/99/0044; GA ČR GA203/02/0023; GA ČR GA203/01/0401; GA AV ČR IAA4031703; GA AV ČR IAA4031103
Institutional research plan: CEZ:AV0Z4031919
Keywords : background electrolytes * capillary zone electrophoresis * multivalent electrolytes
Subject RIV: CB - Analytical Chemistry, Separation
Impact factor: 4.325, year: 2002

Multivalent weak acids and bases are useful components of buffers in electrophoresis. The use of such buffers as background electrolytes (BGEs) in capillary zone electrophoresis (CZE) is, however, risky due to the existence of unsafe regions in the analytical window of the separation. This contribution discusses the problems and shows that multivalent weak species in BGEs bring about the same effects as mixtures of two independent co-ions, i.e., the presence of two centers of symmetry in the electropherograms and the existence of a migrating system zone with a mobility in between these two centers of symmetry. The system zone deteriorates the analytical separation and detection of the analytes in its neighborhood. Illustrative experimental examples for both cationic and anionic CZE are shown and related discussion is given. Finally, some basic rules are formulated to avoid the preparation of risky BGEs.
Permanent Link: http://hdl.handle.net/11104/0059714