Temperature Effect on Enantiomeric Separation of Diacylglycerol Derivatives by HPLC on Various Chiral Columns

Enantiomeric separation of 1,2-diacyl-rac-glycerols (1,2-rac- DGs) as their 3,5-dinitrophenylurethane (3,5-DNPU) derivatives in high-performance liquid chromatography (HPLC) is carried out on chiral columns. One chiral column shows clearly higher enantioselectivity for 1,2-rac-DG enantiomers than the other column in this study. The temperature dependence of the separation factor (α) of enantiomers is determined on these chiral columns. Thermodynamic consideration shows that the free energy (ΔΔG°), enthalpy (ΔΔH°), and entropy differences (ΔΔS°) are not the same among the columns.