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Impact of particle size gradients on the apparent efficiency of chromatographic columns.

Authors :
Codesido, Santiago
Rudaz, Serge
Veuthey, Jean-Luc
Guillarme, Davy
Desmet, Gert
Fekete, Szabolcs
Source :
Journal of Chromatography A. Oct2019, Vol. 1603, p208-215. 8p.
Publication Year :
2019

Abstract

• a dimensionless measure of the particle size gradient steepness was introduced. • about 15–20% gain in efficiency can be expected with particle size gradient. • too large particle size gradient can result in lower efficiencies than monodisperse packing. • large molecules (peptides, proteins) can in principle see the highest gain in efficiency. In this paper, the benefits of using columns packed with particles of decreasing size (particle size gradient) in liquid chromatography was investigated from a theoretical point of view. It is indeed well known that such columns may be useful in gradient elution, since the decrease of particle size along the chromatographic column can provide extra peak focusing effect. In the present contribution, several parameters (i.e., mobile phase gradient steepness, retention times and operating pressures) were considered and the kinetic performance of various types of columns packed with particle size gradient were evaluated. In the best case, about 15–20% gain in efficiency can be expected at a given retention time when utilizing a particle size gradient, compared to constant particle size. Conversely, when fixing efficiency, the analysis time can be decreased by about 15% with an optimal particle size gradient. However, it is also important to keep in mind that a too large a particle size gradient can result in lower efficiencies than a column packed with monodisperse packing. We have introduced the g d value, which is a dimensionless measure of the particle size gradient steepness that measures the relative variation of particle diameter throughout the column with respect to the average. We finally observed that g d = 0.3 - 0.4 provides the highest gain under practically useful conditions. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
00219673
Volume :
1603
Database :
Academic Search Index
Journal :
Journal of Chromatography A
Publication Type :
Academic Journal
Accession number :
138154649
Full Text :
https://doi.org/10.1016/j.chroma.2019.06.048