title: Pre-concentration of non-uniform field electrophoresis for sample introduction of capillary electrophoresis.
abstract: A new sample introduction method of capillary electrophoresis, in which field-amplified sample injection was combined with a pre-concentration of non-uniform field electrophoresis, is presented in this paper. With an additional pre-concentration voltage applied to sample solution, a non-uniform electric field was generated, with which analytical cations or anions were pre-concentrated around an electrode adjacent to the injection end of capillary. After the pre-concentration, analytical ions were injected into the capillary and stacked at the boundary between sample and buffer solution inside capillary by field-amplified injection technique. In contrast to the conventional field-amplified injection, larger concentration factor and higher analytical sensitivity were obtained with the improved pre-concentration method. Its concentration factor was about 10 approximately 15 fold as that of field-amplified sample injection.
authors.affiliation: Department of Chemistry, University of Science and Technology of China, Anhui, Hefei.
authors.forename: L
authors.initials: L
authors.lastname: Yang
authors.forename: Y Z
authors.initials: YZ
authors.lastname: He
authors.forename: W E
authors.initials: WE
authors.lastname: Gan
authors.forename: X Q
authors.initials: XQ
authors.lastname: Lin
authors.forename: Y Q
authors.initials: YQ
authors.lastname: Zhao
authors.forename: Q S
authors.initials: QS
authors.lastname: Qu
mesh_terms: D019075:Electrophoresis, Capillary / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity