Back to Search
Start Over
In situ measurement of the transversal dispersion in ordered and disordered two-dimensional pillar beds for liquid chromatography.
- Source :
-
Analytical chemistry [Anal Chem] 2014 Mar 18; Vol. 86 (6), pp. 2947-54. Date of Electronic Publication: 2014 Feb 28. - Publication Year :
- 2014
-
Abstract
- Using a fully transparent micropillar array chip and an optical "injection" setup capable of writing pulsed and continuous patterns into the flow by uncaging a fluorescent dye, highly detailed measurements of the transversal dispersion process in two-dimensional (2D) chromatographic beds could be made. With the use of water-glycerol mobile phase spanning a wide range of viscosities, the obtained data cover a broad range of reduced velocities (0 < ν < 3000) and show a clear leveling-off of the transversal dispersion coefficient at large reduced velocities. With dependence on the packing density, this leveling-off occurs at a value of about Dtrans/Dmol = 10 (ε = 0.4), Dtrans/Dmol = 4 (ε = 0.6) and Dtrans/Dmol = 2.5 (ε = 0.8). Another interesting observation that could be made is that the effect of the bed order on the observed transversal dispersion process is relatively small. The observed leveling-off in the relation between the measured Dtrans values and the reduced liquid velocity furthermore clearly invalidates the classical Galton-board model, predicting a linear increase of Dtrans with the reduced velocity. On the other hand, it corroborates a recently proposed series-connection transport model for Dtrans in 2D porous media.
Details
- Language :
- English
- ISSN :
- 1520-6882
- Volume :
- 86
- Issue :
- 6
- Database :
- MEDLINE
- Journal :
- Analytical chemistry
- Publication Type :
- Academic Journal
- Accession number :
- 24548065
- Full Text :
- https://doi.org/10.1021/ac403147q