State of the art of shear driven chromatography. Advantages and limitations.
The present paper reports on the experimental difficulties encountered when trying to realize the full potential of shear-driven chromatography in nanochannels. While it theoretically offers the possibility to yield over 10,000 plates per centimetre in a few seconds, the practical realization of this potential requires a detector miniaturisation that is carried to the extreme combined with very high sampling rates. In the present study, a charge coupled device camera and a photomultiplier tube combined with pinhole were tested as detector. Despite the fact that the photomultiplier tube could offer a higher sampling rate and a better sensitivity, the charge coupled device turned out to be better suited for the current set-up because of inevitable problems with the stray-light transported through the glass channel wall. The chemistry of the separation surface was additionally studied getting more homogenous coating, thus higher separation efficiency. Having also carried out a number of mechanical improvements, it is now possible to measure separations at a distance of 8mm downstream from the injection point. This is four times further downstream than ever before while realizing a four components mixture separation in less than 1.5s, with a plate generation velocity of about 2000-7000 plates per second depending on the sample.
Fekete
Veronika
V
Vrije Universiteit Brussel, Department of Chemical Engineering, Pleinlaan 2, 1050 Brussels, Belgium. vfekete@vub.ac.be <vfekete@vub.ac.be>
Clicq
David
D
De Malsche
Wim
W
Gardeniers
Han
H
Desmet
Gert
G
D002853:Chromatography, Liquid / Q000295:instrumentation / Q000379:methods*; D008856:Microscopy, Fluorescence; D036103:Nanotechnology