title: Separation of lidocaine and its metabolites by capillary electrophoresis using volatile aqueous and nonaqueous electrolyte systems.
abstract: The separation of the basic drug lidocaine and six of its metabolites has been investigated both by using volatile aqueous electrolyte system, at low pH and by employing non-aqueous electrolyte systems. In aqueous systems, the best separation of the compounds under the investigated conditions was achieved by using the electrolyte 60 mM trifluoroacetic acid (TFA)/triethylamine (TEA) at pH 2.5 containing 15% methanol. With this electrolyte, all seven compounds were well separated with high efficiency and migration time repeatability. The separations with bare fused-silica capillaries and polyacrylamide-coated capillaries were compared with higher separation efficiency with the latter. On the other hand, near baseline separation of all the seven compounds was also obtained by employing the non-aqueous electrolyte, 40 mM ammonium acetate in methanol and TFA (99:1, v/v), with comparable migration time repeatability but lower separation efficiency relative to the aqueous system.
authors.affiliation: Department of Chemistry, Karlstad University, Sweden.
authors.forename: Z
authors.initials: Z
authors.lastname: Wang
authors.forename: H
authors.initials: H
authors.lastname: Wan
authors.forename: M S
authors.initials: MS
authors.lastname: Anderson
authors.forename: M
authors.initials: M
authors.lastname: Abdel-Rehim
authors.forename: L G
authors.initials: LG
authors.lastname: Blomberg
mesh_terms: D000085:Acetates; D004573:Electrolytes; D019075:Electrophoresis, Capillary / Q000295:instrumentation / Q000379:methods*; D005021:Ethylamines; D006863:Hydrogen-Ion Concentration; D008012:Lidocaine / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism; D015394:Molecular Structure; D015203:Reproducibility of Results; D012997:Solvents; D014269:Trifluoroacetic Acid; D014835:Volatilization
chemical_list: D000085:Acetates; D004573:Electrolytes; D005021:Ethylamines; D012997:Solvents; D008012:Lidocaine; D014269:Trifluoroacetic Acid; C018824:ammonium acetate; C016162:triethylamine