Phase microchannel electrophoresis

In addition to electrophoresis-based collection of DNA in microchannels (see Section 7.7.3), adsorbents have been used to collect and purify DNA. In these cases, microchannels are generally used because of the small quantity of material requiring collection. Using solid phase extraction, sorbent particles of nano- and micro-silica and micro-sized octadecylsilica were immobilized using sol-gel chemistry to hU the microchannels of the microfluidic device [194]. DNA as well as several organic compoimds were evaluated for adsorption and desorption. They showed excellent adsorption, but poor recovery because they were difficult to extract. 

Comparable utilization of the tools of microfabrication for liquid-phase analyses came a decade later, when electrokinetic phenomena were proposed to separate dissolved species on chips the application of a high electric field between the ends of a smaU-diameter column or channel can both transport and separate dissolved species in conductive solution without moving mechanical parts. The concept of chip-CE (capillary electrophoresis) was first described in the patent literature in 1990, wherein CE separations are performed in microfabricated columns or microchannels on planar substrates. At the... 

A stationary phase is a solid material, thin film, or gel that remains motionless relative to the flow of buffer, ions, or current in a microchannel during microchip chromatography, electrochromatography, or electrophoresis. 

Electrokinetic Two-Phase Flows, Figure 6 Schematic of the electrophoresis of a charged particle in a microchannel... 

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