J. of Hunan Agr. Univ. (Natural Sci. Edit.) 38 (1), 102-105 (2012). Catechins are flavanols and the group includes mainly epigallocatechin gallate (EGCG), epigallocatechin (EGC), epicatechin gallate (ECG), and epicatechin (EC), among which EGCG is in majority (50-80 %). Based on investigation of the TLC procedures in literatures for the separation of catechin in tea, an optimized HPTLC system was presented. HPTLC of the extracts of green tea and white tea on silica gel with chloroform – acetone – formic acid 125:75:22. Detection by spraying with 1 % vanillin in concentrated hydrochloric acid and heating at 105 °C for 3 min.

J. Planar Chromatogr. 28, 167-172 (2015). TLC of trans-resveratrol in cosmetic raw materials on RP with methanol - water 3:2. The plate is dried for 3 h. Quantitative determination by fluorescence measurement using a deuterium lamp at 340 nm. The hRF value was 38. The LOD and LOQ were 2 and 6 ng/zone, respectively. The presence of trans-resveratrol in the analyzed samples was additionally confirmed by detection with anisaldehyde reagent.

J. Liq. Chromatogr. Relat. Technol. 39, 308-311 (2016). HPTLC of trans-resveratrol in Physalis peruviana on silica gel with ethyl acetate – cyclohexane – n-butanol 9:9:2. Chemiluminescence was induced by dipping for 1 s into bis(2,4,6-trichlorophenyl)oxalate (TCPO) solution (50 mg TCPO in 36 mL n-butyl acetate, vigorously shaken for 20 min with 0.4 mL 35 % hydrogen peroxyde). After dipping, the_x000D_
wet plate was dried until no light reflection could be seen on the surface. The hRF value for trans-resveratrol was 78. The LOQ was 20 ng/zone.

Rev. Bras. Farmacogn. 27, 162-169 (2017). HPTLC fingerprint of Limonium brasiliense on silica gel with ethyl acetate – anhydrous formic acid – water 18:1:1. Detection by spraying with 1 % methanolic ferric chloride hexahydrate. The hRF values for gallic acid and gallocathechin were 70 and 60, respectively.

J. Planar Chromatogr. 30, 418-422 (2017). HPTLC-DPPH* assay of instant gruels enriched with cranberry fruits on silica gel with acetonitrile – water – chloroform – formic acid 30:2:5:2. Detection by dipping into a freshly prepared 0.1 % methanolic 2,2-diphenyl-1-picrylhydrazyl (DPPH*) solution. The plate was scanned with a flat-bed scanner every minute over an hour. The area of the standard solution of rutin at the concentration of 0.5 mg/mL was adopted as the reference point.

Food Chem. 255, 120-131 (2018). HPTLC of polyphenols (chlorogenic acid and rutin) in the peel, pulp, and the edible part of pepper on silica gel with ethyl acetate – dichloromethane – formic acid – acetic acid – water 100:25:10:10:11. Detection by spraying with Natural Product reagent and anisaldehyde sulfuric acid solution. Qualitative identification under UV 254 and 366 nm.

J. Agric. Food Chem. 34, 477-460 (1986). TLC separation of gingerols, slogaols (zingerone) on silica with hexane - ether 3:7. Detection by UV 254 nm and organoleptically after extraction with methanol.

Chromatographia 27, 297-300, (1989). Study of the effects of acidity of the media on the adsorption of phenol and cresols. Investigation with TLC on silica, silica containing 3% of active carbon and silica containing 6% of active carbon with various solvent systems, using Rf values as a measure of the adsorption content of the solvent mixture on the adsoption of phenol and cresols on the active carbon layer.