On-chip definition of picolitre sample injection plugs for miniaturised liquid chromatography

O’Neill, Alan P; O'Brien, P.; Alderman, J.; Hoffman, D.B.; McEnery, Mairead; Murrihy, John P; Glennon, Jeremy D.

doi:10.1016/s0021-9673(01)00999-2

Cited by 41 publications

(24 citation statements)

References 3 publications

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“…In addition, electrophoretic techniques find abundant application in biomolecular analysis, a tremendous market driver at the present time. On the other hand, chip-based pressure-driven liquid chromatographic (LC) systems have been slow to find extensive interest, and have been pioneered by a handful of workers [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. This is mainly due to lack of ease of flow control as is the case with electrokinetically driven devices where mechanical pumps and * Corresponding author.…”

Section: Introductionmentioning

confidence: 99%

“…In this design, an injection plug of fixed volume is contained in the main channel segment between the two side branches. The design requires use of syringe pumps or a standard HPLC injection valve [6,12,15]. However, it is difficult to assure repeatability using this technique, as the confining segment is easily overflowed, and the extremely low flow rates for sample loading are difficult to obtain.…”

Section: Introductionmentioning

confidence: 99%

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Continuous sampling and analysis by on-chip liquid/solid chromatography

Schlund

Gilbert²,

Schnydrig

et al. 2007

Sensors and Actuators B: Chemical

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This paper describes a lab-on-a-chip device for continuous liquid/solid chromatography measurements. Chromatographic separations of phenolic test solutions as well as of vitamins are illustrating the ability and versatility of the system. The dependence of the peak height and width with respect to the injected plug and the saturation limits of the microchip column have been investigated and good correlation to the theoretical predictions have been observed.The focus of the system design is on simplification of both fabrication complexity and application. To this end, large bore flow-through fluid introduction channels have been integrated onto the chip to allow aliquoting from meso-scale flows of sample (up to tens of milliliters per minute). Repeatable plug injections and reproducible chromatographic separations were achieved in an open-tubular on-chip microcolumn with C 8 stationary phase coating. The entire system allows for a rapid cycle time for multiple analyses, exchange of analyte and mobile phase in less than a minute, and complete cleaning cycles within a few seconds only. This makes it a suitable candidate for on-line process analysis applications.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Continuous sampling and analysis by on-chip liquid/solid chromatography

Schlund

Gilbert²,

Schnydrig

et al. 2007

Sensors and Actuators B: Chemical

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show abstract

“…Therefore, a strategy employing pressure loading in conjunction with electrokinetic dispensing was proposed and studied. This avoids the species bias effect and could be used to load any samples [14][15][16]. This combinational injection method, however, increased the controlling complexity as compared to the complete electrokinetic injection method, since a pump or micropump was necessary to create a pressure drop through the sampling channel.…”

Section: Introductionmentioning

confidence: 99%

Injection by hydrostatic pressure in conjunction with electrokinetic force on a microfluidic chip

Gai

Dai

et al. 2004

Electrophoresis

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A simple method was developed for injecting a sample on a cross-form microfluidic chip by means of hydrostatic pressure combined with electrokinetic forces. The hydrostatic pressure was generated simply by adjusting the liquid level in different reservoirs without any additional driven equipment such as a pump. Two dispensing strategies using a floating injection and a gated injection, coupled with hydrostatic pressure loading, were tested. The fluorescence observation verified the feasibility of hydrostatic pressure loading in the separation of a mixture of fluorescein sodium salt and fluorescein isothiocyanate. This method was proved to be effective in leading cells to a separation channel for single cell analysis.

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“…There are two major modes for introducing a sample liquid into the separation field: electrokinetic injection [2][3][4][5] and pressure-driven injection. [6][7][8] Electrokinetic injection is the most commonly used injection method for performing electrophoresis and electrochromatography on microfabricated devices. With this method, no mechanical devices are demanded, and injection is relatively easily achieved.…”

Section: Introductionmentioning

confidence: 99%