The Effect of Particle Monodispersity in HPLC Column Performance

Abstract

Many developments in silica particles used in liquid chromatography have been well documented over the years. The move from irregular silica to spherical silica, the decrease in particle size from >5µm particle in HPLC to sub-2-µm particle size in UHPLC, the improved silica purity of type B silica over that of type A silica, and more recently the adoption of superficially porous particles versus 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 high performance liquid chromatography (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.