NMR investigations of stationary phases

An overview of the application of solid-state and suspended-state NMR spectroscopy for the characterization of stationary phases is given. Solid-state Si-29 NMR spectroscopy reveals valuable information about the variety and quantity of the surface species formed in the modification reaction. Solid-state C-13 NMR spectroscopy gives an insight into the dynamic properties of the immobilized ligands and ligand organization. With the help of H-1 and C-13 suspended-state NMR spectroscopy, investigations can be performed in the presence of a mobile phase. Thus, the structural and dynamic properties of the stationary phase under real-life chromatographic conditions can be derived from the NMR investigations. These findings can be directly correlated with the resulting chromatographic separation behaviour.