SummaryLinear solvation energy relationships (LSERS) were used to quantitatively compare the relative contributions of dipolarity/polarizahility, hydrogen bonding, and other types of intermolecular interactions to retention and selectivity using various hulk mobile phase components. Using experimental conditions which differ only by the composition of the bulk mobile phase component, the factors which cause selectivity to differ between HPLC, subcritical fluid chromatography and supercritical fluid chromatography were deconvoluted. Heptane-based HPLC mobile phases showed superior selectivities towards analytes which differ in hydrogen bond donating ability, gas-to-hexadecane partition coefficient and dipolarity/polarizability. Subcritical fluid chromatography with HFC- 134a (1,1,1,2-tetrafluoroethane) as the bulk fluid produced superior selectivities for analytes which differ in hydrogen bond accepting ability and excess molar refraction properties. Many of these factors showed temperature dependences which act to attenuate or accentuate the particular intermolecular interaction.