title: Large volume sample stacking of positively chargeable analytes in capillary zone electrophoresis without polarity switching: use of low reversed electroosmotic flow induced by a cationic surfactant at acidic pH.
abstract: A simple and effective way to improve detection sensitivity of positively chargeable analytes in capillary zone electrophoresis more than 100-fold is described. Cationic species were made to migrate toward the cathode even under reversed electroosmotic flow caused by a cationic surfactant by using a low pH run buffer. For the first time, with such a configuration, large volume sample stacking of cationic analytes is achieved without a polarity-switching step and loss of efficiency. Samples are prepared in water or aqueous acetonitrile. Aromatic amines and a variety of drugs were concentrated using background solutions containing phosphoric acid and cetyltrimethylammonium bromide. Qualitative and quantitative aspects are also investigated.
authors.affiliation: Faculty of Science, Himeji Institute of Technology, Kamigori, Hyogo, Japan. jquirino@sci.himeji-tech.ac.jp
authors.forename: J P
authors.initials: JP
authors.lastname: Quirino
authors.forename: S
authors.initials: S
authors.lastname: Terabe
mesh_terms: D000818:Animals; D002021:Buffers; D019075:Electrophoresis, Capillary / Q000379:methods*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D012680:Sensitivity and Specificity
chemical_list: D002021:Buffers