Slurry concentration effects on the bed morphology and separation efficiency of capillaries packed with sub-2μm particles

1.1 μm Superficially porous particles for liquid chromatography

“…Based on previous studies from other groups and current research in our laboratory, it has been found that for totally porous particles and non-porous particles, a high slurry concentration produces columns with higher efficiency [43]. Concentrations found in the literature varied from 7 to 40% (w/v%) and a concentration of 2.5% (w/v%) was found to work best for 1.0 m totally porous particles packed in our laboratory [4,15,17].…”

“…The decrease in the a-term may be attributed to the predicted effect of the increased packing rate for the higher slurry concentrations which lead to improved radial homogeneity. [3] The higher slurry concentration has also been found to produce a denser wall region resulting in a more homogeneous packed bed [43]. The reduction in the apparent cterm is likely due to a decrease in the velocity-dependent coupled a-term.…”

“…Based on the studies by Bruns et al, slurry concentrations up to 100 mg/mL may prove beneficial [43]. The specific concentration at which the performance begins to decrease or column packing becomes impossible was not investigated.…”

Implementation of high slurry concentration and sonication to pack high-efficiency, meter-long capillary ultrahigh pressure liquid chromatography columns

“…Previous studies have indicated that the differences in these regions are dependent on slurry concentration [16,17]. Detailed understanding of the packing microstructure has guided empirical packing studies to obtain well performing columns.…”

Evaluation of preparative hydrodynamic chromatography of silica stationary phase supports

“…Because these particles are widely used in ultra-high pressure liquid chromatography (UHPLC) applications, reduction of the relative standard deviation (RSD) is desirable. While there have been a variety of findings regarding the impact of RSD on band broadening in different column types [2][3][4][5][6][7], two recent reports focused on capillary columns demonstrated the relationship between column performance and particle size segregation within columns packed with the same particle batch [8,9]. These two studies suggest refined particle batches may allow for improved and more consistent performance in capillary LC.…”