Determination of sorbent polarity and selectivity by linear regression of retention indices

Abstract A regression equation for the description of retention indices through molecular parameters of sorbates is proposed. Electron polarizability, dipole moment, molar volume, the molecular connectivity indices of first order and electron-acceptor and electron-donor energetic constants were chosen as descriptors. The regression coefficients obtained relate to the ability of a surface to effect some sorbate—sorbent interactions. The validity of the expression was shown for a wide range of sorbent polarity. A high significance of the steric factor G = 1 χ/ V m was revealed. A set of test sorbates was specified for routine determinations of sorbent polarity.