Particles, Pressure, and System Contribution: The Holy Trinity of Ultrahigh-Performance Liquid Chromatography

The last decade has witnessed how liquid chromatography columns and instruments changed from long,bulky columns with relatively large fully porous particles operated at modest pressures (100-200 bar), to short compact columns with small superficially porous particles operated at ultrahigh pressures (12001500 bar). This (r)evolution has resulted in a tremendous increase in achievable separation performance or decrease in analysis time, but requires a good knowledge of optimal chromatographic conditions for each separation problem and, concomitant, the right instrument configuration.