ABSTRACT
This chapter presents the general principles of aqueous normal phase (ANP) chromatography, a technique that has features of both reversed-phase and hydrophilic interaction chromatography. It is a unique chromatography format and while some types of stationary phases exhibit a limited ANP capability, it is silica hydride-based materials that are most successful in this mode and have the broadest range of applications. A variety of approaches and stationary phases are available for the separation of mixtures or analyses of specific compounds based on the chemical and structural properties of the analyte. A large fraction of current chromatographic methods utilize a format that revolutionized separation science; chemically bonded stationary phases that are fabricated on silica as a support material with hydrophobic moieties attached to the surface. There have been numerous reports in the literature describing a broad array of stationary phases based on ordinary silica.
