Many developments in silica particles used in liquid chromatography (LC) have been well documented over the years. The move from irregular silica to spherical silica, the decrease in particle size from >5μm particle in high performance liquid chromatography (HPLC) to sub-2-μm particle size in ultrahigh-pressure LC (UHPLC), the improved silica purity of type B silica over that of type A silica, and more recently the adoption of superficially porous particles compared to traditional fully porous particles. One area of development that has been discussed less, and is still open to debate, is the particle size distribution (PSD) of these chromatographic materials. In this article, we discuss the move towards improved monodispersity of silica particles for use in HPLC and how the use of monodisperse particles can impact the resulting chromatographic parameters such as reduced plate height and column impedance. On a practical level, we review how the reduction of PSD impacts efficiency, backpressure, and sensitivity.
Authors:
Ken Butchart, Co-Founder & Director, Fortis Technologies
Mark Woodruff, Co-Founder & Director, Fortis Technologies