Separation of Selected Bile Acids by TLC. VII. Separation by Reversed Partition HPTLC

Abstract

Selected bile acids: cholic acid (C), glycocholic acid (GC), glycodeoxycholic acid (GDC), chenodeoxycholic acid (CDC), deoxycholic acid (DC), lithocholic acid (LC), and glycolithocholic acid (GLC) were investigated with the use of reversed phase high performance thin‐layer chromatography on RP18W (E. Merck, #1.14296), RP18 (E. Merck, #1.05914), RP2 (E. Merck, #1.13726), and CNF₂₅₄ (E. Merck, #1.12571) plates using methanol–water, organic mixture (acetonitrile–methanol 50:50, v/v)–water, acetone–water, dioxane–water, and acetonitrile–phosphate buffer (pH 4.60) as mobile phases, in different volume compositions.

The obtained separations were carried out on the basis of separation factors values ΔR_F and R_S. None of the applied chromatographic conditions enabled completion of the separation of all examined bile acids. Five neighboring bile acids, i.e., LC/DC, CDC/GLC, GLC/C, C/GDC, GDC/GC, were separated only when CNF₂₅₄ plates and the mobile phase acetone–water, 50:50; v/v were used. The biggest problem was to separate DC from CDC. These bile acids were separated only on RP2 plates by using methanol–water, 65:35, v/v as a mobile phase.

Keywords:

• Bile acids
• RP‐HPTLC
• RP18W
• RP18
• RP2
• CNF₂₅₄
• Separation parameters