This application note shows two examples where the pi electron differences between methanol and acetonitrile are used to obtain different selectivity.
When choosing an organic solvent for the mobile phase, an analyst should always consider the properties of the analytes. This is especially true for unique stationary phases such as the CORTECS Phenyl Column. Pi electron deficient solvents such as methanol, can help to strengthen the pi-pi interaction of an analyte and the phenyl stationary phase, whereas pi electron rich solvents, such as acetonitrile, can minimize that interaction and allow other influences to dominate. By understanding the interplay between the analytes, the mobile phase, and the stationary phase, analysts can tune chromatographic conditions to have greater success in their separations.