Reduction of Taylor-Aris dispersion by lateral mixing for chromatographic applications.

Westerbeek, Eiko Y; Bomer, Johan G; Olthuis, Wouter; Eijkel, Jan C T; De Malsche, Wim · Lab Chip · 2020

basic_science · Level V

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Abstract

Chromatographic columns are suffering from Taylor-Aris dispersion, especially for slowly diffusing molecules such as proteins. Since downscaling the channel size to reduce Taylor-Aris dispersion meets fundamental pressure limitations, new strategies are needed to further improve chromatography beyond its current limits. In this work we demonstrate a method to reduce Taylor-Aris dispersion by lateral mixing in a newly designed silicon AC-electroosmotic flow mixer. We obtained a reduction in κ<sub>aris</sub> by a factor of three in a 40 μm × 20 μm microchannel, corresponding to a plate height gain of 2 to 3 under unretained conditions at low to high Pe values. We also demonstrate an improvement of a reverse-phase chromatographic separation of coumarins.