Microchip extraction of catecholamines using a boronic acid functional affinity monolith.

A novel solid phase extraction microchip with a boronic acid functional affinity monolithic disc was developed in this work. Vinyl phenylboronic acid-ethylene glycol dimethacrylate co-polymer monoliths, which have pore sizes up to 20 μm, were investigated for extraction of catecholamines using adsorption and desorption studies in a batch system. Desorption yields of greater than 90% were achieved for catecholamines at pH 3 and below.

Development of a micro-total analysis system (μ-TAS) for the determination of catecholamines.

In this study, the first micro-total analysis system (μ-TAS) for catecholamines (dopamine, epinephrine, and norepinephrine) analysis in which preconcentration, separation, and determination steps were integrated on a microchip was developed. Electrophoresis microchips in a variety of channel lengths and designs were produced in borofloat glass for the μ-TAS studies. Chambers for the preparation of monolithic disks were formed in the microchips at the intersection of the injection and separation channels.

The potential use of fiber optics for detection in microchip separation and miniaturized flow-cell systems.

This article evaluates the potential of using fiber optics as a detection tool during electrophoretic separations or identification and quantification of analytes in miniaturized systems, including microchips. This paper covers reports in the literature from 1989 to June 2002. The articles have been chosen based on various aspects of the instrumentation including the microchip substrates, channel size and geometry, pathlength, fiber and detector types, light source, separation conditions, detection limits, and applications-all with the goal of comparing and contrasting optical detections.