J. Planar Chromatogr. 11, 230-232 (1998). TLC of flavone derivatives (apigenin, apigenin-7-O-glucoside, luteolin, luteolin-4-O- and -7-O-glucoside) on RP-18 with methanol - water - acetic acid 25:25:3. Visualization by spraying with a methanolic solution of 1% diphenylboric acid aminoethyl ester (NP) and 5% polyethylene glycol (PEG). Preparative TLC was performed on conventional thick silica gel and RP-18 with ethyl acetate - formic acid - water 6:1:1 and methanol - water - acetic acid 25:25:3. The spots were analyzed by UV after extraction. Acid hydrolysis of the isolated flavonoids was carried out directly on the TLC plate after application by dipping (of the application zone) into 5 N HCl in methanol - water 1:1 and leaving at 110°C for 45 min to hydrolyze.

and Vaccinium vitis-idaea. L. J. Planar Chromatogr. 13, 101-105 (2000). HPTLC of flavonoids (i. a. quercetin, avicularin, hyperin, isoquercetin) on silica gel by two- and three-step gradient elution with mixtures of toluene, hexane, ethyl acetate and methanol for glycosides and multiple development for aglycones. Videodocumentation was achieved by use of videoscanning equipment. Visualization under UV 254 or 365 nm; or by spraying with one of the three reagents: (i) 10% KOH in methanol; (ii) 1% solution of FeCl3; and (iii) Gibbs reagent. Quantitation by densitometry at 254 nm.

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).