A new frontal electroelution approach that can be used for the preconcentration of amino acids in in-line solid-phase extraction-capillary electrophoresis (SPE-CE) has been developed. A single capillary was employed featuring a short monolithic SPE column created inside the capillary via photo-initiated, free-radical polymerisation of 3-sulfopropyl methacrylate and butyl methacrylate monomers. A weak electrolyte of dilute H2SO 4, pH 2.9, was found to promote adsorption of the amino acids onto the SPE column. Elution of the amino acids was achieved using a dual solvation/ion-exchange transient boundary mobilised via EOF by using a strong electrolyte containing 62.5 mM ethylenediamine, pH 2.9 with H2SO 4 and 40% (v/v) acetonitrile. Using these two electrolytes, tryptophan was adsorbed onto the SPE column in weak electrolyte and eluted via a frontal electroelution mechanism in the strong electrolyte. Injections up to 20 min, corresponding to over 14 column volumes (or 1400% of the capillary volume) of sample provided quantitative extraction of tryptophan from the weak electrolyte and were eluted without any loss in efficiency. This represents a practical increase of approximately 300-fold when compared to a typical hydrodynamic injection occupying 5% of the capillary volume. © 2005 Elsevier B.V. All rights reserved.

Item Type:	Refereed Article
Research Division:	Chemical Sciences
Research Group:	Analytical Chemistry
Research Field:	Separation Science
Objective Division:	Expanding Knowledge
Objective Group:	Expanding Knowledge
Objective Field:	Expanding Knowledge in the Chemical Sciences
Author:	Breadmore, MC (Professor Michael Breadmore)
ID Code:	43016
Year Published:	2006
Web of Science® Times Cited:	25
Deposited By:	Chemistry
Deposited On:	2006-08-01
Last Modified:	2007-04-02
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