Pushing the performance limits of reversed-phase ultra high performance liquid chromatography with 1.3μm core-shell...

Innovative columns made with very small core-shell particles (1.0-1.4μm) were investigated over a wide experimental space using state-of-the-art ultra high performance liquid chromatography (UHPLC) instruments. Among the columns tested is one that is now commercially available and is made with 1.3μm core-shell particles consisting of non-porous cores about 0.9μm in size and porous shells <0.2μm thick. This work demonstrated that exceptionally low observed minimum plate heights of 2.2μm could be obtained using columns packed with 1.3μm particles, corresponding to a plate count of over 450,000 plates/m. It was shown that only low volume columns allow operation under optimal conditions with current top-of-the-line UHPLC instruments. It was also demonstrated that the loss in performance caused by frictional heating effects remains negligible. Finally, the practical utility of these columns was confirmed with several real-world applications requiring extreme resolving power (i.e. peptide mapping, sample typical of metabolomic studies and crude human insulin). The performance achieved was compared to that of a reference UHPLC column packed with 1.7μm fully porous particles. The column packed with 1.3μm particles gave peak capacity values that were 20-40% higher than the reference column for the same analysis time.