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

• Published in: Journal of separation science Vol. 29; no. 13; pp. 2091 - 2097
• Main Authors: Acedo-Valenzuela, María-Isabel, Galeano-Díaz, Teresa, Mora-Díez, Nielene, Silva-Rodríguez, Antonio
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 01-08-2006; WILEY‐VCH Verlag; Wiley
• Subjects: Acetonitrile stacking; Analysis; Analytical chemistry; Antidepressive Agents, Tricyclic - analysis; Antidepressive Agents, Tricyclic - blood; Biological and medical sciences; Blood Chemical Analysis - methods; Chemistry; Chromatographic methods and physical methods associated with chromatography; Chromatography, Micellar Electrokinetic Capillary - methods; Electroinjection; Electrophoresis, Capillary - methods; Exact sciences and technology; Experimental design; General pharmacology; Humans; Medical sciences; Other chromatographic methods; Pharmacology. Drug treatments; Salts; Surface response methodology; Tricyclic antidepressants; Trace analysis; Acetonitrile stacking; Biological fluid; ctroinjection / Experimental design / Surface response methodology / Tricyclic antidepressants; Chemical analysis; Capillary electrophoresis; Psychotropic; Injection; Tricyclic compound; Optimization; Blood; Chemical enrichment; Ultraviolet detector; Experimental design; Antidepressant agent; Response surface; Field enhanced sample injection; Blood serum; Chemometrics
• ISSN: 1615-9306; 1615-9314
• DOI: 10.1002/jssc.200600068

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.