title: Ionic liquids as modifiers to improve the separation efficiency of nonaqueous capillary electrophoresis with high electric field strengths.
abstract: A method of nonaqueous capillary electrophoresis based on ionic liquids was developed with a high electric field (800 V/cm). The ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate was used as modifier to improve the separation efficiency; trishydroxymethylaminomethane and sodium cholate were used as background electrolytes in methanol and acetonitrile. The ionic liquids used in this paper have the ability to assist in the separation of hydrophobic mixtures while maintaining adequate background current. They can also improve the efficiency of heat diffusion in the capillary because they demonstrate high thermal conductivity. The developed method was used to analyze kaempferol-3-O-glucoside, 7-hydroxy-8-methoxycoumarin and 8-hydroxycoumarin-7-O-glucoside in samples of Sinacalia tangutica. The obtained quantities of the three analytes in the flower of Sinacalia tangutica were 0.27, 0.18 and 0.57%, respectively. The recovery was determined with standard addition and the results were 85.1-100.4%.
authors.affiliation: State Key Laboratory of Applied Organic Chemistry and Department of Chemistry, Lanzhou University, Lanzhou 730000, P. R. China.
authors.forename: Shengda
authors.initials: S
authors.lastname: Qi
authors.forename: Huige
authors.initials: H
authors.lastname: Zhang
authors.forename: Jinhua
authors.initials: J
authors.lastname: Zhu
authors.forename: Xingguo
authors.initials: X
authors.lastname: Chen
authors.forename: Liye
authors.initials: L
authors.lastname: Qi