Separation of Selected Bile Acids by TLC. VIII. Separation on Silica Gel 60F₂₅₄ Glass Plates Impregnated with Cu(II), Ni(II), Fe(II), and Mn(II) Cations

Abstract

The aim of our study was to examine the following bile acids: cholic acid (C), glycocholic acid (GC), glycolithocholic acid (GLC), deoxycholic acid (DC), chenodeoxycholic acid (CDC), glycodeoxycholic acid (GDC), and lithocholic acid (LC). In the present study, to separate a/m bile acids using adsorption thin layer chromatography at 18°C, the glass plates precoated with silica gel 60F₂₅₄ (#1.05715), were impregnated with 1%, 2.5%, and 5% aqueous solutions of the following salts: CuSO₄, MnSO₄, NiSO₄, and FeSO₄. The mixtures of n‐hexane–ethyl acetate–acetic acid in the volume compositions: 22:20:5; 25:20:2; 25:20:5, and 25:20:8 were used as mobile phases. These mobile phases were not effective for the separation of bile acids on non impregnated silica gel 60F₂₅₄ plates at 18°C. The plates impregnated with the salts whose application resulted in ΔR_F≥0.05 and R_S>1 for all neighboring pairs of examined bile acids were considered the most effective for bile acids separation. It was observed that impregnation of silica gel 60F₂₅₄ glass plates with aqueous solutions of CuSO₄, MnSO₄, NiSO₄, and FeSO₄ improved the separation of GC/GDC and C/GLC, which separated poorly on glass plates precoated with non impregnated silica gel 60F₂₅₄ in adsorption TLC at 18°C.

Keywords:

• Bile acids
• Adsorption TLC
• Silica gel 60F₂₅₄ glass plates
• Impregnation with metal cations