The benefits of sub-2 micrometer chromatographic supports have largely focused separation technologies towards ultrahigh pressure liquid chromatography, UHPLC. Theoretically, sorbents on this scale provide higher separation efficiencies and shorter separation times. True benefit from these materials is dependent, however, on homogeneous packing of the sorbent into a column. This is complicated by the smaller particle’s requirement of significantly increased packing pressure and presents a major challenge in the creation of a uniform bed structure.
Previous results have suggested that combination of high slurry concentration and sonication during packing would create homogeneous bed microstructures and yield highly efficient capillary columns. In work published in the Journal of Chromatography A, researchers in the Jorgenson Group, present the effect of sonication while packing very high slurry concentrations.
A series of six, 1 m × 75 micrometer internal diameter columns were packed with 200 mg/mL slurries of 2.02 micrometer bridged-ethyl hybrid silica particles. Three of the columns underwent sonication during packing and yielded highly efficient separations with reduced plate heights as low as 1.05.