USP L78 designation/classification column. A silane ligand that consists of both reversed-phase (an alkyl chain longer than C8) and anion-exchange (primary, secondary, or tertiary amino groups) functional groups chemically bonded to porous high quality silica gel particles, 3, 5 and 10 um particle size. Mixed-mode HPLC column with dual mechanism of interaction. Retains and separates compounds based on reversed-phase, anion-exchange and cation-exclusion mechanisms. Ideal column for analysis of surfactants. Robust and reproducible.