Synthesis and characterization of C13 to C18 stationary phases by monomeric, solution polymerized, and surface polymerized approaches

A series of bonded phases were synthesized from consecutive length alkylsilanes ranging from C13 through C18, with three different bonding chemistries (monomeric, solution polymerized, and surface polymerized) at each phase length. The phases were characterized in terms of methylene selectivity, shape selectivity, and band broadening. No significant chromatographic differences were found to result from the synthetic routes, except that the different bonding chemistries provide a different range of bonding densities. For bonding densities ranging from 2 to 8 μmol/m2, a linear increase in methylene selectivity was observed with increasing bonding density. Over the narrow range of bonded phase lengths investigated, shape selectivity is more dependent on density than phase length.