The thermodynamic behaviors for some proteins and small molecules in hydrophobic interaction chromatography are studied in the temperature range of 21-80℃. The thermodynamic parameters (ΔH°, ΔS°, ΔG°) of these proteins are determined by using Van't Hoff relationship (lnk'-1/T). By using the obtained standard entropy change (ΔS°) and free energy change (ΔG°), the conformational change of the proteins is judged in chromatographic process. The linear relationships between ΔH° and ΔS° can be used to evaluate "compensation temperature" (β) at the protein denaturation and identify the identity of the protein retention mechanism in hydrophobic interaction chromatography.

Key words: THERMODYNAMICS, RETENTION, PARAMETER, CONFORMATION, PROTEIN, HYDROPHOBIC INTERACTION CHROMATOGRAPHY, THERMODYNAMIC ANALYSIS