Capillary electrochromatography chip-based

Microfluidic chip-based electrochromatography (p-CEC), stemming from capillary electrochromatography (CEC), is a powerful separation technique combining the versatility offered by high-performance liquid chromatography (HPLC) with the high separation efficiency of... 

Microfluidic Chip-Based Electrochromatography, Fig. 3 General fabrication ofCAs-CHIPby embedding square capillaries into the PDMS microfluidic devices (Reprinted with permission from [19])... 

Li HF, Zeng HL, Chen ZF, Lin JM (2009) Chip-based enantioselective open-tubular capillary electrochromatography using bovine serum albumin-gold nanoparticle conjugates as the stationary phase. Electrophoresis 30 1022-1029... 

Capillary electrochromatography has experienced rapid progress during the last decade, expanding from 17 publications in 1994 to 191 in 2007. This has also led to several books and reviews [93-104] and analytical instrumentation is readily commercially available [105]. The developments in CEC include research on optimum stationary phases (polymer or silica based, adsorbed or imprinted, etc.), mobile phases (aqueous electrolytes with/without admixture of organic solvents or pseudophases) and apparatus design (open-tubular, packed or monolithic capillaries) up to lab-on-a-chip devices for pTAS [107]. 

Lazar et al. " have recently demonstrated the first example of interfacing chip electrochromatography with mass spectrometric detection. The glass microchip contained a methacrylate-based monolith as well as an integrated capillary tip for ESI. The straight 130-p.m wide and 50-p.m deep main channel of the chip contained a 5 to 6-cm long separation section that led directly to the ESI... 

An entirely different concept in analytical separations is provided by capillary electrophoresis (CE) in which the flow of liquid is generated by electro-osmotic flow (EOF) driven by an external electric field. The major advantage of this approach is the essentiaUy flat plug flow profile that leads to intrinsically more narrow elution peaks than the parabolic flow profiles characteristic of pressure-driven viscous flows. In capillary zone electrophoresis (CZE) separation is achieved by superimposing the different electrophoretic mobihties of the solutes on to the EOF. In electrochromatography the separation is achieved as in packed column HPLC but using an EOF to generate flow of the mobile phase past the stationary phase particles. The importance of these EOF-based techniques is their application to miniaturized devices, lah-on-a-chip or micro total analysis systems. Such devices that can be directly interfaced to a mass spectrometer via an ESI source are currently under intense development. 

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