Use of the kinetic plot method to compare the efficiency and resolution of liquid-phase separation techniques based on different driving forces

Much effort has been devoted to improving the capability of separation techniques. The lower the separation volume and the higher the plate number the better the separation. HPLC, UHPLC, CE, and shear-driven chromatography have different separation characteristics. It is shown how the kinetic plot method, originally developed for pressure-driven LC, can be extended to electrically-driven and shear-driven LC. With this extension, the separation speed of pressure-driven, electrically driven, and shear-driven LC can now be compared on a universal basis, i.e. by comparing the separation efficiency or resolution that can be obtained in a given time. As an illustrative example, the separation of coumarin dyes is considered.