Evaluation of a simple hyphenated system for flow injection solid-phase pre-concentration and capillary electrophoresis

Abstract

Nesse trabalho apresentamos um sistema hifenizado envolvendo as duas técnicas analíticas: eletroforese capilar (CE) e análises por injeção em fluxo (FIA), denominado de FIA-CE. Parâmetros como a influência do fluxo e a natureza do eluente frente ao sistema CE foram avaliados. O sistema demonstrou-se promissor quanto à possibilidade de aplicações em diferentes áreas da química analítica. O aumento da sensibilidade foi da ordem de 660% devido ao emprego de colunas de troca iônica no sistema FIA. Esse resultado comprova o grande potencial do sistema FIA-CE.In this work, the development and evaluation of a hyphenated flow injection-capillary electrophoresis system with on-line pre-concentration is described. Preliminary tests were performed to investigate the influence of flow rates over the analytical signals. Results revealed losses in terms of sensitivity of the FIA-CE system when compared to the conventional CE system. To overcome signal decrease and to make the system more efficient, a lower flow rate was set and an anionic resin column was added to the flow manifold in order to pre-concentrate the analyte. The pre-concentration FIA-CE system presented a sensitivity improvement of about 660% and there was only a small increase of 8% in total peak dispersion. These results have confirmed the great potential of the proposed system for many analytical tasks especially for low concentration samples.

Analytical chemistry in Brazil: healthy and growing

“…108 Hyphenation of a flow injection system to capillary electrophoresis was exploited for on-line preconcentration on an anionic resin column. 297 Sensitivity improvement was estimated as 660%, without critically affecting resolution (peak dispersion increased in 8%).…”