Marine Drugs 21(1), 2 (2023). Samples were methanol extracts of cultivated marine bacteria Thalassomonas actiniarum, T. viridans and T. haliotis (Colwelliaceae),  as well as cholesterol, cholic acid, and deoxycholic acid as standards. TLC on silica gel with n-hexane – ethyl acetate – methanol – acetic acid 20:20:5:2. After drying at room temperature, visualization by spraying with phosphomolybdic acid (10 % in ethanol) and heating with a heat-gun. For isolation of cholic acid (hRF 80), present in all samples, preparative TLC on silica gel with the same mobile phase, the corresponding band was scraped off with a surgical blade and extracted with methanol overnight. The isolated cholic acid was identified by LC-MS.

J. Planar Chromatogr. 33, 271-279 (2020). Two-dimensional HPTLC of cholic, ursodeoxycholic, chenodeoxycholic, deoxycholic, and lithocholic bile acids on silica gel with 0.0001 M cetylpyridinium chloride at pH 9 with the addition of aliphatic alcohol modifiers 4 % 1-butanol (direction II) and 0.6 % 1-pentanol (direction II). Detection by drying the plate for 2-3 min in the oven at 120 ºC, followed by spraying with 8 % sulfuric acid in ethanol. Qualitative determination under UV light at 365 nm.

J. AOAC Int. 102, 708-713 (2019). TLC of snake bile in 20 species from three families (Elapidae, Colubridae, and Viperidae) on silica gel with xylene – isopropanol – methanol – glacial acetic acid – water 80:40:30:20:3. Detection by spraying with a 10% sulfuric acid ethanol solution, followed by heating at 105 ºC.  Qualitative identification under UV light at 366 nm. TLC coupled with quadrupole–time-of-flight–MS analysis of each zone was used for compound identification and evaluation.

J. Planar Chromatogr. 28, 380-385 (2015). HPTLC of taurocholic acid (1), glycodeoxycholic acid (2) and taurodeoxycholic acid (3) in ten Thai edible plants on silica gel with chloroform - methanol - acetic acid 7:2:1. Quantitative determination by absorbance measurement at 366 nm. Linearity was in the range of 34-2200 ng/zone for (1), 33-2100 ng/zone for (2) and 30-1900 ng/zone for (3). LOD and LOQ were 10 and 50 ng/zone for (1), 20 and 40 ng/zone for (2) and 10 and 50 ng/zone for (3). The intermediate precision was below 1.2 % (n=6). Average recovery for (1) to (3) was 99, 100 and 100 %, respectively.

J. Chromatogr. 497, 139-146 (1989). TLC of faecal bile acids on silica with isooctane - 2-propanol - acetic acid 30:10:1 for the 1st development and isooctane - ethyl acetate - acetic acid 10:10:2 for the 2nd. Detection by dipping into 0.2% 2,7-dichlorofluorescein ethanol solution. Quantification by fluoro densitometry at 366 nm. Good correspondence between this method and GC.

IV. Comparison of separation of studied bile acids by the use of cluster analysis. J. Liq. Chrom. & Rel. Technol. 27, 2987-2995 (2004). TLC of bile acids (cholic, glycocholic, glycolithocholic, deoxycholic, chenodeoxycholic, glycodeoxycholic, and lithocholic acid) on silica gel and a mixture of silica gel and Kieselguhr with n-hexane - ethyl acetate - acetic acid in various volume compositions. Detection with 10 % aqueous sulfuric acid followed by heating at 120 °C for 20 min. On silica gel the separation of glycocholic from glycodeoxycholic acid was difficult, on the mixed silica gel - Kieselguhr layer the separation of cholic acid from glycolithocholic acid. The obtained results indicate that similar analysis can be an alternative method for the estimation of chromatographic separations of studied bile acids.

Lipids 17, 477-482 (1982). Preparative TLC of microbially produced metabolites of lithocholic acid and lithocholic acid-3 alpha-sulfate on silica with dichloromethane-methanol 95:5. Detection by spraying with anisaldehyde, followed by heating. The following metabolites were isolated: isolithocholic acid, 5 beta-cholanic acid, 3-keto-lithocholic acid, 5 alpha -cholestone and delta 3-cholenic acid.

Shaanxi Provin. J. Med. (Shaanxi Yixue Zazhi) 18, 28-30 (1989). TLC of free bile acids on silica with isooctane - isoproyl ether - acetic acid - butanol - water 10:5:5:3:1. Detection by spraying with a solution of phosphomolybdic acid. Quantification by densitometry.