Planta med. 65, 671-673 (1999). Preparative TLC of e.g., 3,4-dihydro-5-hydroxy-7-methoxy-4- (4'-methoxyphenyl)coumarin on silica gel with dichloromethane - hexane - ethyl acetate 6:3:1, of 3,4-dihydro-4-(4'-hydroxyphenyl)-5,7-dihydroxycoumarin, 3,4-dihydro-5-hydroxy-7-methoxy- 4-(4'-hydroxyphenyl)coumarin, and 3,4-dihydro-5,7-dihydroxy-4-(4'-methoxyphenyl)coumarin on silica gel with 1. dichloromethane - hexane - methanol 6:3:1 and 2. dichloromethane - methanol 9:1. Detection under UV.

J. Planar Chromatogr. 15, 433-436 (2002). TLC of (+)-catechin, (-)-epicatechin and (+/-)-catechin on cellulose, preferably prewashed with water - acetic acid 19:1, with 1-butanol - water - acetic acid 4:2:1. Detection by dipping in anisaldehyde - sulfuric acid reagent and with vanillin - phosphoric acid reagent. The work shows the importance of optimization of prewashing, pre-conditioning, and use of the correct development chamber and detection reagent in the TLC analysis procedure.

with and without red heartwood. J. Planar Chromatogr. 17, 350-354 (2004). TLC of (+)-catechin and (-)-epicatechin on silica gel with diisopropyl ether - formic acid 9:1. Detection by spraying with vanillin-sulfuric acid reagent and heating at 120 °C for 5 min. Quantitative determination by absorbance measurement at 513 nm.

J. Planar Chromatogr. 19, 463-466 (2006). Preparative RP-HPTLC of anthocyanin extracts (e. g. malvidine) on silica gel with five-step gradient elution with different concentrations of toluene - acetonitrile - water - formic acid - n-butanol - 2-propanol and resp. addition of tert-butylmethyl ether. After extraction of the third zone from the layer, HPTLC on RP-18 as the best stationary phase with a three-step gradient elution using methanol - water - formic acid in different ratios. Quantitative determination by absorbance measurement at 470 nm.

J. Planar Chromatogr. 23, 230-232 (2010). HPTLC of (+)-catechin, (-)-epicatechin, (-)-epigallocatechin, (-)-epigallocatechin gallate, (-)-epicatechin gallate, procyanidin B2, procyanidin A2, and methylxanthines (theobromine and caffein) on cellulose with n-propanol - water - acetic acid 20:80:1 in a horizontal chamber. Detection by dipping for 1 s into 4-dimethylaminocinnamaldehyde detection reagent. Quantitative determination by absorbance measurement at 655 nm. By densitometry LOD for (-)-epicatechin and procyanidin B2 was 0.2 and 2 ng/zone, respectively; LOQ was 0.4 ng and 4 ng/zone, respectively. These limits were lower by a factor 50 for (-)-epicatechin and by a factor of 10 for procyanidin B2 than those obtained by HPLC. The TLC method gave a more accurate result for the (-)-epicatechin content of baking chocolate than the HPLC method which was also more time-consuming.

Food Chem. 156, 94-99 (2014). TLC of epigallocatechin gallate (1), gallic acid (2) and caffeine (3) on silica gel with dichloromethane - acetone - formic acid 8:7:1. Detection by dipping into 5 % methanol - sulfuric acid reagent, followed by heating at 105 °C for 3 min. Quantitative determination of (1) as gallic acid equivalents by absorbance measurement at 270 nm (epigallocatechin gallate (EPCG) was calculated and expressed as gallic acid equivalents because the EPCG standard is very expensive). The hRF values for (1) to (3) were 54, 69 and 80. Linearity was in the range of 500-5000 ng/zone for (2) and 200-2400 ng/zone for (3). The intermediate/inter-day/intra-day precisions were below 2 % (n=3). The LODs and LOQs were 400 and 500 ng/zone for (2) and 180 and 200 ng/zone for (3), respectively. Recoveries were between 94.9 and 100.0 % for (2).

Journal of Ethnopharmacology 163, 192-202 (2015). TLC of the aqueous extract (crude vs. after tannin removal on a polyamide column) of the kino (red hydrosoluble exudate) of Pterocarpus erinaceus on silica gel with s-butanol – water – acetic acid 14:5:5. Detection with vanillin-hydrochloric acid reagent revealed catechic tannins and related polyphenols as dark pink zones. These compounds showed hRfs between 0 and 40, and above 60 in the case of the crude extract, whereas they almost did not appear in the tannin-free fraction. The extracts were also submitted to HPLC-HRMS, allowing the identification of epicatechin monomer in both extracts and of oligomers in the crude extract only.

J. AOAC Int. 99, 374-379 (2016). HPTLC of glabridin in the roots of Glycyrrhiza glabra on silica gel with hexane – ethyl acetate – chloroform 5:4:3. Quantitative determination by absorbance measurement at 285 nm. The hRF value of glabridin was 48. Linearity was in the range of 50-500 ng/zone. The LOD and LOQ were 10 ng/zone and 30 ng/zone, respectively. Intermediate precisions were below 2 %. Recovery was between 100.6 and 102.0 %. Compared to a validated HPLC method there was no statistically significant difference in the mean values.