| Popis: |
The hydrophilic/lipophilic material, Sephadex LH-20, shows strong retention of lipophilic molecules in aqueous media. The major retention force is believed to be entropic hydrophobic bonding. This interpretation is supported by the following experimental results: (a) separation as a function of the length of the hydrocarbon chain of the molecule; (b) stronger retention as the temperature rises or (c) when electrolyte is added to the eluant; and (d) the opposite behavior of solutes in the hydrophilic material, Bio-Gel. In organic solvents, however, hydrogen bonding and a little understood polar interaction are the dominating adsorptive forces. |
