Separation of Selected Bile Acids by TLC. V. Influence of Temperature on the Separation

Abstract

Adsorption thin‐layer chromatography (TLC) was used to study the influence of temperature, 18°C and 40°C, on retention and separation of selected bile acids, that is, cholic acid (C), glycocholic acid (GC), glycolithocholic acid (GLC), deoxycholic acid (DC), chenodeoxycholic acid (CDC), glycodeoxycholic acid (GDC), and lithocholic acid (LC). The mixture of n‐hexane–ethyl acetate–acetic acid, in various volume compositions, was used as a mobile phase. Chromatographic experiments were performed on the following stationary phases: glass plates precoated with silica gel 60F₂₅₄ without concentrating zone (#1.05715); glass plates precoated with silica gel 60F₂₅₄ with concentrating zone (#1.11798); aluminum plates precoated with silica gel 60F₂₅₄ (#1.05554), and silica gel 60 (#1.05553), and also on aluminum plates precoated with the mixture of silica gel 60 F₂₅₄ and Kieselguhr F₂₅₄ (#1.05567). It was proven that the temperature of 40°C improved the separation of GC from GDC performed on aluminum plates precoated with silica gel 60 (#1.05715, #1.05554, and #1.05553). However, when this temperature is used, the separation of CDC from DC poses the biggest problem. The obtained results indicate that the separation of some bile acids can be improved by proper choice of temperature. The temperature of 40°C causes the change of bile acids elution order.

Keywords:

• Bile acids
• Adsorption TLC
• Temperature of separation