Column-in-valve designs to minimize extra-column volumes

We report on the design and performance of in-house built column cartridges that can be directly screwed into ports a commercial rotor-stator valve to minimize extra-column band broadening pressure-drop losses when pursuing ultra-fast separations such as those needed in 2D 3D-LC separations. Two basic designs were evaluated compared with results obtained screw-in cartridge. The system produces an low 0.05 0.1 ?L2 for employed UV-detector set-up. Despite these very values, separation efficiency fabricated cartridge columns was low, corresponding reduced minimal plate height around h=7 at best, which, 1.7 ?m particle 26.4 mm long corresponds number theoretical plates N=2200 under isocratic conditions. A similar poor dimensions using same One possible explanation observed could found inner diameter (i.d. =0.75 1 mm) sub 2-?m particles, falls region diameters that, according literature models, is most likely suffer from inherent packing problems.