Synthesis, characterization, and high-performance liquid chromatographic evaluation of C14 stationary phases containing branched and unbranched alkyl groups

Reversed-phase materials with branched and unbranched alkyl groups were prepared by modifying porous, spherical silica gel in a two-step reaction—immobilization of a trifunctional alkoxysilane (3-glycidoxypropyltrimethoxysilane) on the silica surface followed by reaction with a branched and an unbranched octanoic acid. The chromatographic sorbents were characterized by solid-state ²⁹Si and ¹³C NMR spectroscopy. The chromatographic behaviour of the stationary phases was evaluated by use of a test mixture according to the Standard Reference Material 870 set from the US National Institute of Standards and Technology, in order to study the effect of branched and unbranched alkyl chains.