Quantitative retention relationships as a function of mobile and C18 stationary phase composition for non-cogeneric solutes.

Twelve non-homologous solutes with a wide range of functional groups were chromatographed on a series of well-characterized stationary phases with a range of methanol-water mobile phases. Retention correlations were found for quantum mechanically calculated molecular parameters. These parameters, the total molecular energy, and the maximal excess electronic charge difference, were found to be better descriptors of retention than the dipole moment or fragmental constants. The implication of these results in terms of retention mechanisms on reversed-phase materials are discussed.