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Nonaqueous capillary electrophoresis with alcoholic background electrolytes: Separation efficiency under high electrical field strengths
Author(s) -
Palonen Sami,
Jussila Matti,
Porras Simo P.,
Hyötyläinen Tuulia,
Riekkola MarjaLiisa
Publication year - 2002
Publication title -
electrophoresis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.666
H-Index - 158
eISSN - 1522-2683
pISSN - 0173-0835
DOI - 10.1002/1522-2683(200202)23:3<393::aid-elps393>3.0.co;2-x
Subject(s) - capillary electrophoresis , electrolyte , chemistry , analytical chemistry (journal) , chromatography , separation process , electrophoresis , capillary action , analyte , joule heating , methanol , propanol , theoretical plate , materials science , electrode , organic chemistry , composite material
The effect of high voltage on capillary electrophoresis (CE) separations of anionic analytes in nonaqueous separation media was investigated. Methanol, ethanol, 1‐propanol, and 1‐butanol were tested as background electrolyte (BGE) solvents. Experiments were carried out with a laboratory‐built CE instrument suitable for high‐voltage separations. Potentials up to 60 kV were applied with reversed polarity to generate unusually high field strengths ( e.g. 2000 Vcm –1 ) and so achieve fast and efficient separations. Highest separation efficiencies were obtained with propanol as BGE solvent, and the dependency of the efficiency on the separation voltage was more or less linear. With the other alcohols, separation efficiency decreased or remained roughly constant with increasing absolute voltage. The separation efficiencies are discussed in terms of longitudinal diffusion, Joule heating, and analyte interaction with the capillary wall. Capillary preconditioning had a varied effect on the separations in the different BGEs as the BGE and the conditioning process affected the electroosmotic flow (EOF) velocity and direction.