Thermogravimetric studies of silica-based chemically bonded phases

摘要

Silica-based chemically bonded phases are widely used as chromatographic packings in reversed-phase liquid chromatorgraphy. Their properties are strongly affected by the nature of silica support and its pretreatment as well as by the type of attached ligands, their density, secondary bonding effects, end-capping, etc. The objective of this work was to study the surface properties of silica-based phases as a function of the bonded ligand density. For this purpose several octyl bonded phases were synthesized using the same silica support. The differences in the surface properties of these phases were characterized by high-resolution thermogravimetry, nitrogen adsorption, elemental analysis and solid state NMR.