Performance in (Ultra‐)high‐performance liquid chromatography—How to qualify and optimize instruments in practice

This paper investigates the suitability of an ultra‐high‐performance liquid chromatography/high‐performance liquid chromatography hybrid system for ultra‐high‐performance liquid chromatography applications. Thus, the effect of extra column band broadening, the gradient system, and the injection system were tested and optimized according to their capabilities. An increase of the theoretical plate number up to a factor of two is achieved by the optimization of the extra column volume into the typical ultra‐high‐performance liquid chromatography range (