Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7608688 | Journal of Chromatography A | 2018 | 13 Pages |
Abstract
First, the validity of this proposed stochastic model was tested by adjusting the predicted to the observed reduced van Deemter plots of a 2.1â¯mmâ¯Ãâ¯50â¯mm column packed with 2â¯Î¼m BEH-C18 fully porous particles (FPPs). An excellent agreement was found for uiâ¯=â¯0.93uc, a result fully consistent with the FIB-SEM observation (uiâ¯=â¯0.95uc). Next, the model was used to measure uiâ¯=â¯0.94uc for 2.1â¯mmâ¯Ãâ¯100â¯mm column packed with 1.6â¯Î¼m Cortecs-C18 superficially porous particles (SPPs). The relative velocity bias across columns packed with SPPs is then barely smaller than that observed in columns packed with FPPs (+6% versus + 7%). uw=1.8ui is measured for a 75â¯Î¼mâ¯Ãâ¯1â¯m capillary column packed with 2â¯Î¼m BEH-C18 particles. Despite this large wall-to-center velocity bias (+80%), the presence of the thin and ordered wall packing layer has no negative impact on the kinetic performance of capillary columns. Finally, the stochastic model of long-range eddy dispersion explains why analytical (2.1-4.6â¯mm i.d.) and capillary (<400â¯Î¼m i.d.) columns can all be packed efficiently (1â¯3) with sub-2â¯Î¼m particles and with 1â¯Î¼m particles, respectively.
Keywords
Related Topics
Physical Sciences and Engineering
Chemistry
Analytical Chemistry
Authors
Fabrice Gritti,