Quantitative analysis by microchip capillary electrophoresis – current limitations and problem-solving strategies

Revermann, Tobias; Götz, Sebastian; Künnemeyer, Jens; Kärst, Uwe

doi:10.1039/b711165g

Cited by 45 publications

(44 citation statements)

References 74 publications

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“…EOF originates from diffused counter-ions within electrical double layer (EDL) that drift under a tangentially applied field and drag along the liquid layers in a nearly uniform plug flow. Nevertheless, EOF rates are sensitive to surface properties, which may undesirably vary with the pH of the background solution as well as with irreversible adsorption of the charged analytes [16,17]. Thus, EOF can be accurately and rapidly switched by simply modulating the field.…”

Section: General Aspectsmentioning

confidence: 99%

Induced hydraulic pumping via integrated submicrometer cylindrical glass capillaries

Cao

Yobaş

2014

Electrophoresis

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Here, we report on a micropump that generates hydraulic pressure owing to a mismatch in EOF rates of microchannels and submicrometer cylindrical glass capillaries integrated on silicon. The electrical conductance of such capillaries in the dilute limit departs from bulk linear behavior as well as from the surface-charge-governed saturation in nanoslits that is well described by the assumption of a constant surface charge density. The capillaries show rather a gradual decrease in conduction at low salt concentrations, which can be explained more aptly by a variable surface charge density that accounts for chemical equilibrium of the surface. The micropump uses a traditional cross-junction structure with ten identical capillaries integrated in parallel on a side arm and each with a 750 nm diameter and 3 mm length. For an applied voltage of 700 V, a hydraulic pressure up to 5 kPa is generated with a corresponding flow velocity nearly 3 mm/s in a straight field-free branch 20 μm wide, 10 μm deep, and 10 mm long. The micropump utility has been demonstrated in an open tubular LC of three fluorescently labeled amino acids in just less than 20 s with minimal plate height values between 3 and 7 μm. The submicrometer capillaries are self-enclosed and produced through a unique process that does not require high-resolution advanced lithography or wafer-bonding techniques to define their highly controlled precise structures.

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Section: General Aspectsmentioning

confidence: 99%

Induced hydraulic pumping via integrated submicrometer cylindrical glass capillaries

Cao

Yobaş

2014

Electrophoresis

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“…The transference of the adopted buffer from conventional to microchip format gave a poor resolution, mainly due to the short effective length of the microchip compared to conventional capillary, and another buffer, prepared with cyclodentrins HP-b-CD and CTAB, was needed to achieve suitable separation. Finally, an important review dealing with quantitative analysis using CE microchips indicates the analytical potency of these miniaturized devices [133]. Other relevant examples are, among others: the ultrafast detection and simultaneous analysis of genetically modified maize [127]; the analysis of neuroactive amines in fermented beverages using a portable and versatile microfabricated CE microchip system, which has been used in the identification of biomarkers such as amino acids, amines, amino sugars and nucleobases in other fields [128]; artificial dyes [129,130]; and toxic alkaloids (colchicines, aconitine, strychnine and nicotine) [131,132].…”

Section: Food Analysismentioning

confidence: 99%

Miniaturized Systems for Analytical Separations II: Systems Based on Electroosmotic Flow (EOF)

Ríos

Escarpa

Simonet

2009

Miniaturization of Analytical Systems

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“…Despite the trend towards increasing utilization of microfluidic chips in analytical chemistry, confirmed by the steadily growing number of scientific publications focusing on microfluidic chips (Fig. 1), chip-CE has to overcome significant challenges in comparison with classical capillary-based CE, especially in regard to its relative complexity and a number of technical hurdles, ruggedness, reliability and ease of operation [49].…”

Section: Conventional Capillary-based Ce Versus Ce-on-a-chipmentioning

confidence: 99%

Portable capillary-based (non-chip) capillary electrophoresis

Ryvolová

Preisler

Brabazon

et al. 2010

TrAC Trends in Analytical Chemistry

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Miniaturized, portable instrumentation has been gaining popularity in all areas of analytical chemistry. Capillary electrophoresis (CE), due to its main strengths of high separation efficiency, relatively short analysis time and low consumption of chemicals, is a particularly suitable technique for use in portable analytical instrumentation. In line with the general trend in miniaturization in chemistry utilizing microfluidic chips, the main thrust of portable CE (P-CE) systems development is towards chip-based miniaturized CE. Despite this, capillary-based (non-chip) P-CE systems have certain unmatched advantages, especially in the relative simplicity of the regular cylindrical geometry of the CE capillary, maximal volume-to-surface ratio, no need to design and to fabricate a chip, the low costs of capillary compared to chip, and better performance with some detection techniques. This review presents an overview of the state of the art of P-CE and literature relevant to future developments. We pay particular attention to the development and the potential of miniaturization of functional parts for P-CE. These include components related to sample introduction, separation and detection, which are the key elements in P-CE design. The future of P-CE may be in relatively simple, rugged designs (e.g., using a short piece of capillary fixed to a chip-sized platform on which injection and detection parts can be mounted). Electrochemical detection is well suited for miniaturization, so is probably the most suitable detection technique for P-CE, but optical detection is gaining interest, especially due to miniaturized light sources (e.g., light-emitting diodes).

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Quantitative analysis by microchip capillary electrophoresis – current limitations and problem-solving strategies

Cited by 45 publications

References 74 publications

Induced hydraulic pumping via integrated submicrometer cylindrical glass capillaries

Induced hydraulic pumping via integrated submicrometer cylindrical glass capillaries

Miniaturized Systems for Analytical Separations II: Systems Based on Electroosmotic Flow (EOF)

Portable capillary-based (non-chip) capillary electrophoresis

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