Study of retention interactions of solute and stationary phase in the light of the solvation model theory Original Research Article

Specific constants for 18 polymers taken from the literature were determined by multiple linear regression (MLR) analysis. Cavity formation/dispersion plays a central role in the low polarity stationary phases (octacosane) where the other interactions were unimportant. The dipolar interactions prevail in the polar stationary phases (poly(methyl acrylate) (PMA)). The hydrogen-bond solvent acidity/solute basicity was negligible for all of them. The solvation parameter model has been applied to the above system (373 K) and to two other solute-stationary phases sets (393–394 K), also taken from the literature. Correlations of the characteristic solvent constants with their polarities were investigated, and the effects of solute and stationary phase polarity on the above interactions were evaluated. For a given solute, the plots of cavity formation/dispersion (nonpolar) and polar (electronic polarizability, dipole induction/orientation and hydrogen-bond complexation) interactions versus the stationary phase polarity yielded decreasing and increasing straight lines, respectively. However, for a given stationary phase, these two interactions increased with increasing solute polarity. Also, the changes of the above interactions with the stationary phase polarity are sensitive to the solute polarity, and the changes of the same interactions with the solute polarity depend on the stationary phase polarity.