J. Chromatogr. 614, 315-323 (1993). TLC of diethylstilbestrol and zeranol on silica with dichloromethane - methanol - 2-propanol 97:1:2. Visualization with iodine - starch, or by spraying with 0.05% aqueous solution of diazonium dyes, and exposure to NH3 vapor for 30 sec and heating at 80 °C for 2 min.

Dtsch. Apoth. Ztg. 139, 835-836 (1999). TLC of ethinyl estradiol (using methyltestosterone, norethisterone, progesterone, estradiol benzoate, testosterone propionate and mestranol as reference substances) on silica gel with toluene - ethyl acetate 7:3; without chamber saturation). The plate is left for 15 min in the air after application. Detection under UV 254 nm (ethinyl estradiol can not be recognized!), and after spraying with 20% ethanolic sulfuric acid, heating at 110°C for 5 min under daylight and UV 360 nm. Approved procedure for identity and quality test.

II. One-dimensional and two-dimensional TLC. J. Liq. Chrom. Rel. Technol. 27, 2031-2038 (2004). TLC of 7 bile acids (chenodeoxycholic, deoxycholic, cholic, glycocholic, lithocholic, glycodeoxycholic, and glycolithocholic acid) on silica gel with n-hexane - ethyl acetate - acetic acid 5:4:1 in the first dimension and chloroform - n-butanol - acetic acid - water 1:16:1:1 in the second dimension. Detection by spraying with 10 % sulfuric acid followed by heating at 120 °C for 20 min. The 2D technique allowed the complete separation of all the bile acids studied.

Trends Anal. Chem. 82, 250-267 (2016). This review describes the application of capillary electrochromatography in food safety and food quality, from the first application in 1997, including the use of TLC for sample preparation in the analysis of sterols in the oils of sunflower, canola rice bran, olive (extra virgin), soybean, corn, peanut, grapeseed, and hazelnut.

leaves. J. Planar Chromatogr. 31, 377-381 (2018). HPTLC of ursolic acid and β-sitosterol in the leaves of Paederia foetida on silica gel with toluene ‒ ethyl acetate ‒ formic acid 80:20:1. Detection by spraying with anisaldehyde–sulfuric acid reagent, followed by heating at 110 °C for 1 min. Quantitative determination by absorbance measurement at 550 nm. The hRF values for (1) and (2) were 22 and 38, respectively. Linearity was between 100 and 500 ng for (1) and (2). LOD and LOQ were 40 and 121 ng for (1) and 50 and 152 ng for (2). The intermediate precision was <2 % (n=3). Recovery ranged from 97.2 % to 99.2 % for (1) and 98.0 % to 99.2 % for (2).

(TLC chromatographic analysis for the quantitative estimation of the fecal bile acid composition). TLC of cholic acid, chenodesoxy cholic acid, desoxy cholic acid, lithocholic acid and ursodesoxy cholic acid on silica with isooctane - isopropanol - acetic acid 30:10:1 and/or isooctane - ethyl acetate - acetic acid 10:10:2. Derivatization with 2 % ethanolic solution of 2,7-dichlorofluoresceine. Densitometric quantification by fluorescence. Fiber rich polysaccharides (dietary fibers) elevate fecal bile acids and their metabolites. The possible role of this diet in relation to fecal bile acid concentration and large bowel cancer is discussed.

J.Trad.Chin.Med (Zhongguo Zhongyao Zazhi) 14, 466-468 (1989). TLC of D7- stigmastenol and fructose on silica with cyclohexane - ethyl acetate 4:1, and benzene - acetic acid - methanol 15:6:4. Quantification by densitometry (absorbance) at 540 nm and 500 nm.

Anal. Chim. Acta 275, 147-162 (1993). HPTLC of the anabolic residues in biological samples on silica with seven solvent systems in one or in two dimensions. Detection under UV 366 nm. Also, HPLC and GC/MS. Discussion of the influence of the matrix and the applied methods on the results.