title: Conductivity detection in capillary zone electrophoresis: inspection by PeakMaster.
abstract: A simple rule stating that the signal in conductivity detection in capillary zone electrophoresis is proportional to the difference between the analyte mobility and mobility of the background electrolyte (BGE) co-ion is valid only for systems with fully ionized electrolytes. In zone electrophoresis systems with weak electrolytes both conductivity signal and electromigration dispersion of analyte peaks depend on the conductivity and pH effects. This allows optimization of the composition of BGEs to give a good conductivity signal of analytes while still keeping electromigration dispersion near zero, regardless of the injected amount of sample. The demands to achieve minimum electromigration dispersion and high sensitivity in conductivity detection can be accomplished at the same time. PeakMaster software is used for inspection of BGEs commonly used for separation of sugars (carbohydrates, saccharides) at highly alkaline pH. It is shown that the terms direct and indirect conductivity detection are misleading and should not be used.
authors.affiliation: Faculty of Science, Charles University, CZ-128 040 Prague 2, Czech Republic.
authors.forename: Michal
authors.initials: M
authors.lastname: Jaros
authors.forename: Tomoyoshi
authors.initials: T
authors.lastname: Soga
authors.forename: Tom
authors.initials: T
authors.lastname: van de Goor
authors.forename: Bohuslav
authors.initials: B
authors.lastname: Gas
mesh_terms: D004553:Electric Conductivity; D004573:Electrolytes / Q000737:chemistry; D019075:Electrophoresis, Capillary / Q000379:methods*
chemical_list: D004573:Electrolytes