| Popis: |
Solute—sorbent interactions were studied by using the retentions of aliphatic and aromatic hydrocarbons, ethers and alcohols on macroporous methacrylate copolymers (H+, Li+, Na+, K+, Rb+, Cs+ and Ag+) containing sulphopropyl groups. The individual contributions to the overall Kovats index were calculated by multiple linear regression with parameters characterizing the solute (electron polarizability, dipole moment) and sorbent (surface concentration of groups, ionic radius of the cation). In the case of aromatic hydrocarbons and ethers the contribution of the solute is decisive (98%), while for alcohols the contribution of the sorbent increases to as much as 22%. The results confirm classical views according to which low-polarity compounds are separated due to non-specific interactions and polar compounds are separated due to specific solute—sorbent interactions. A similar picture of the interactions was provided by correlations in which the solute was characterized by Hammett and Taft substitution constants. |
