Peak compression effects in packed-column supercritical fluid chromatography

Peak compression phenomena are studied and applied to the analysis of lipid emulsion samples of clevidipine. Alcohols and water are found to generate system peaks on a silica column with 2-propanol-modified carbon dioxide. The retention times of the system peaks are found to vary as a function of type (water or alcohol) and chromatographic conditions (pressure, temperature, and modifier). By selecting an appropriate system peak generator and chromatographic conditions, the peak compression effect is created for the analysis of an emulsion sample of clevidipine solution containing water, methanol, and acetonitrile. The presence of buffer or lipids in the sample does not affect the peak compression phenomena.