title: Amperometric detection in the presence of carbon nanotubes dispersed in background electrolyte: Evaluating its suitability for capillary electrokinetic chromatography separations of polyphenolic compounds.
abstract: This work reports on the positive effects observed upon both the separation and analytical signals in electrophoretic separations of selected phenolic compounds when using aqueous BGE containing carbon nanotubes (CNTs) in connection to electrochemical detection (ECD). The influence of the presence of surfactant-coated CNTs in the BGE upon the amperometric response of probe compounds was evaluated under hydrodynamic regime in capillary flow injection experiments as well as electrophoretic separations. Among the surfactants employed to disperse CNTs within BGE, SDS shows the best results in terms of dispersion stability and degree of dispersion of the CNTs. ECD allows working with BGEs containing CNTs concentrations of, at least, 24.0 mg/L without increasing of baseline noise, on the opposite to that reported when using UV-visible detection, and the presence of CNTs in the BGE improves the electrochemical response of some of the tested compounds. These benefits were reflected in higher sensibility in the electrochemical signal and additional improved resolution in the electrophoretic separation of (±)-catechin and sinapic acid when using these BGE containing CNTs.
authors.affiliation: Dpto. Química Analítica y Análisis Instrumental, Universidad Autónoma de Madrid. C/ Francisco Tomás y Valiente, Madrid, Spain.
authors.forename: Mónica
authors.initials: M
authors.lastname: Moreno
authors.affiliation: Dpto. Química Analítica y Análisis Instrumental, Universidad Autónoma de Madrid. C/ Francisco Tomás y Valiente, Madrid, Spain.
authors.forename: Alberto
authors.initials: A
authors.lastname: Sánchez Arribas
authors.affiliation: Dpto. Química Analítica y Análisis Instrumental, Universidad Autónoma de Madrid. C/ Francisco Tomás y Valiente, Madrid, Spain.
authors.forename: Esperanza
authors.initials: E
authors.lastname: Bermejo
authors.affiliation: Dpto. Ciencias Analíticas. Universidad Nacional de Educación a Distancia. Pº Senda del Rey, Madrid, Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: Zapardiel
authors.affiliation: Dpto. Química Analítica y Análisis Instrumental, Universidad Autónoma de Madrid. C/ Francisco Tomás y Valiente, Madrid, Spain.
authors.forename: Manuel
authors.initials: M
authors.lastname: Chicharro
mesh_terms: D015102:3,4-Dihydroxyphenylacetic Acid / Q000032:analysis; D020374:Chromatography, Micellar Electrokinetic Capillary / Q000379:methods*; D004298:Dopamine / Q000032:analysis; D004573:Electrolytes; D016014:Linear Models; D037742:Nanotubes, Carbon / Q000737:chemistry*; D010636:Phenols / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification
chemical_list: D004573:Electrolytes; D037742:Nanotubes, Carbon; D010636:Phenols; D015102:3,4-Dihydroxyphenylacetic Acid; D004298:Dopamine
keywords: Amperometric detection; Carbon nanotubes; Electrokinetic chromatography; Polyphenols; Pseudostationary phase