title: Response surface methodology in the development of a stacking-sensitive capillary electrophoresis method by field-amplified injection for the analysis of tricyclic antidepressants in the presence of salts.
abstract: The work presented here explores the possibilities of the electrokinetic injection (EK) to achieve sensitive methods for the determination of tricyclic antidepressants in biological samples (serum). The addition of ACN to the sample, with high content in salts, causes stacking at the tip of the capillary, in a similar way as for hydrodynamic injection. An experimental design with the response surface methodology has been used to find the optimum composition of the matrix of the sample (sodium chloride and ACN percentages) and the conditions for the EK (water-plug length, time, and voltage of injection) in few experiments. The composition of the separation buffer was the same as utilized in a previous paper. The use of a bubble capillary to reach lower detection limits implies a loss of the resolution and requires a new optimization. Finally, a comparison between electrokinetic and hydrodynamic injections is made.
authors.affiliation: Departamento de Quimica Analitica, Facultad de Ciencias, Universidad de Extremadura, Badajoz, España.
authors.forename: María-Isabel
authors.initials: MI
authors.lastname: Acedo-Valenzuela
authors.forename: Teresa
authors.initials: T
authors.lastname: Galeano-Díaz
authors.forename: Nielene
authors.initials: N
authors.lastname: Mora-Díez
authors.forename: Antonio
authors.initials: A
authors.lastname: Silva-Rodríguez
mesh_terms: D000929:Antidepressive Agents, Tricyclic / Q000032:analysis* / Q000097:blood; D001774:Blood Chemical Analysis / Q000379:methods; D020374:Chromatography, Micellar Electrokinetic Capillary / Q000379:methods; D019075:Electrophoresis, Capillary / Q000379:methods*; D006801:Humans; D012492:Salts
chemical_list: D000929:Antidepressive Agents, Tricyclic; D012492:Salts