Electroconcentration by using countercurrent due to pressurized flow and electrophoretic mobility

Hori, Akihiro; Matsumoto, Takatoshi; Nimura, Yuji.; Ikedo, Masakazu; Okada, Hideki; Tsuda, Toshitaka

doi:10.1021/ac00068a027

Cited by 25 publications

(23 citation statements)

References 5 publications

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“…The first report of this approach was in 1990 by Tsuda and Muramatsu [110] for electrochromatography, and was subsequently followed in 1993 by Hori et al [111] who introduced the term 'countercurrent electroconcentration' to describe this approach. Analytes were concentrated at the edge of the electric field, essentially a very sharp step gradient, with a 50-fold increase in sensitivity obtained.…”

Section: Countercurrent Electroconcentrationmentioning

confidence: 99%

Recent advances in enhancing the sensitivity of electrophoresis and electrochromatography in capillaries and microchips

2007

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Poor sensitivity is considered to be one of the major limitations of electrophoretic separation methods, particularly when compared to traditional liquid chromatographic techniques. To address this issue, various in-line preconcentration techniques have been developed over the past 15 years, ranging in power and complexity, and there are now a number of well understood approaches routinely capable of providing a 10,000- to 100,000-fold increase in sensitivity, as well as several that can be pushed above a million. Furthermore, these have been achieved with particularly troublesome and often difficult samples, such as those having high salinity from a biological or environmental origin. This review will discuss the most common methods for improving the sensitivity of CE, CEC and microchip version of these, with particular attention to those approaches developed over the last five years.

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Section: Countercurrent Electroconcentrationmentioning

confidence: 99%

Recent advances in enhancing the sensitivity of electrophoresis and electrochromatography in capillaries and microchips

2007

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“…As long as electric field is being applied, the analyte will continue to be excluded and concentrate. A method with similar principles was published by Hori et al, but the technique employed large volumes and a 1.5 mm diameter tube [36]. Initial work by Polson et al utilized this electrophoretic exclusion technique and demonstrated the ability to exclude and concentrate 200 nm particles at the entrance of a 20 mm i.d.…”

Section: Introductionmentioning

confidence: 99%

Electrophoretic exclusion for the selective transport of small molecules

et al. 2009

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A novel method capable of differentiating and concentrating small molecules in bulk solution termed "electrophoretic exclusion" is described and experimentally investigated. In this technique, the hydrodynamic flow of the system is countered by the electrophoretic velocity to prevent a species from entering into the channel. The separation can be controlled by changing the flow rate or applied electric field in order to exclude certain species selectively while allowing others to pass through the capillary. Proof of principle studies employed a flow injection regime of the method and examined the exclusion of Methyl Violet dye in the presence of a neutral species. Methyl Violet was concentrated almost 40 times the background concentration in 30 s using 6 kV. Additionally, a threshold voltage necessary for exclusion was determined. The establishment of a threshold voltage enabled the differentiation of two similar cationic species: Methyl Green and Neutral Red.

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“…An early study by Hori et al [14] showed the connection of a large diameter tube (1.5 mm) between two reservoirs containing several milliliters of solution, where the flow was set to oppose the electrophoretic migration of selected species. The electrophoretic migration was larger than the flow rate, which prevented the charged species from being transferred from the reservoir thus concentrating those materials.…”

Section: Introductionmentioning

confidence: 99%

A study on the condition for differential electrophoretic transport at a channel entrance

2007

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Electrophoretic differential transport of ionic species in a solution moving from a large reservoir into a small channel is investigated numerically. The system setup is similar to the experiments of Polson, Savin, and Hayes (J. Microcol. Sep. 2000, 12, 98), where the bulk flow into a fused-silica capillary was driven by a pressure differential. A critical condition for achieving the defined differential transport near the channel entrance is found and this condition is solely determined by a dimensionless parameter when the geometry of the system is prescribed. This dimensionless parameter is the ratio between the electrophoretic migration velocity of the species based on the apparent electric intensity and the centerline fluid velocity of the fully developed channel flow. Species concentration distributions are also computed for various conditions. A separation technique can be derived from the experimental condition where a targeted division of species can be created at the channel entrance.

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Electroconcentration by using countercurrent due to pressurized flow and electrophoretic mobility

Cited by 25 publications

References 5 publications

Recent advances in enhancing the sensitivity of electrophoresis and electrochromatography in capillaries and microchips

Recent advances in enhancing the sensitivity of electrophoresis and electrochromatography in capillaries and microchips

Electrophoretic exclusion for the selective transport of small molecules

A study on the condition for differential electrophoretic transport at a channel entrance

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