Diffusion NMR Investigation of Solvent Interaction with Reversed-Phase HPLC Column Material


Julia Aponte, Errol V. Mathias and Yong Ba

Department of Chemistry and Biochemistry

California State University of Los Angeles


The exploration of HPLC mobile phase dynamics provides a more quantitative perspective on retention mechanisms dependent on column efficiency. We have studied the interaction of SBC-18 reversed-phase column material with hexane, ethyl acetate and ethylene glycol solvents using 1H Diffusion Ordered Spectroscopy (DOSY). Hexane is the least polar solvent and ethylene glycol the most. Our results suggest that the change in diffusion coefficient of the solvent in the presence of column material is a function of the polarity of the solvent and also its specific solvating properties with the C-18 silica surface.