Merck, 50867-U, Ascentis® Express F5, 2 μm UHPLC Column

Ascentis® Express 2.0 μm F5 is a high-speed, UHPLC column based on a Fused-Core® particle design. This particle design exhibits very high column efficiency due to the shallow diffusion paths in the 0.4 μm thick porous shell and the small overall particle size of 2 μm. The bonded, endcapped, dimethylpentafluorophenylpropyl stationary phase of Ascentis® Express 2.0 μm F5 provides a stable, reversed phase packing with electron-deficient phenyl rings due to the presence of electronegative fluorines. In addition to forming pi-pi and mildly steric interactions, F5 phases also retain compounds by polar interactions. Having polar and non-polar character, F5 phases can show dual-mode retention behavior, sometimes producing a “U-shaped” retention as a function of acetonitrile content of the mobile phase, with retention increasing at both low and high concentrations of ACN (reversed-phase and HILIC retention modes). Ascentis® Express 2.0 μm F5 can be used for basic, acidic, or neutral compounds with alternate selectivity from C18.