J. of Modern Trad. Chinese Med. 16 (2), 144-150 (2014). Shushenling Jiaonang capsule is a herbal TCM for the treatment of neurasthenia, neurosis, menopausal syndrome, etc. For quality control, TLC (1) for Salvia miltiorrhiza, on silica gel with toluene – ethyl acetate 19:1, detection under white light; (2) Schisandra chinensis, on silica gel with petroleum ether (30-60 ºC) – ethyl formate – formic acid 15:5:1, detection under UV 254 nm; (3) for Glycyrrhiza uralensis, on silica gel with toluene – ethyl acetate – methanol 7:3:1, detection by spraying with 10 % sulfuric acid in ethanol and heating at 105 ºC until the zones are clearly visualized, evaluation under white light; (4) Panax ginseng, on silica gel with chloroform – methanol – water 13:7:2, detection by spraying with 10 % sulfuric acid in ethanol and heating at 105 ºC until the zones are clearly visualized, evaluation under white light.

J. Planar Chromatogr. 30, 164-169 (2017). HPTLC of hexyl nicotinate on silica gel with acetone ‒ n-hexane 3:7. Chemical stability analysis was performed in aqua–ethanolic solutions stored in ordinary and quartz flasks heated at 40 °C and exposed to UV radiation at 254 nm. The main products of chemical changes of hexyl nicotinate are the substances with hRf 37 and 68. Preliminary identification of the decomposition products was achieved by GC–MS analysis.

J. Planar Chromatogr. 30, 113-120 (2017). HPTLC of brilliant green, green fat, green S, iochrome black, oil red, natural red, rhodamine, patent blue, brilliant blue, brilliant black, azorubin, ponceau 4R, allura red, tartrazine, 1-aminoanthraquinone, (4-[2-pirydylazo]resorcinol), quinoline yellow, thymol blue and curcumin on RP-18 by isocratic elution with different concentrations of methanol in water (0-100 % v/v) with addition of 100 mM trifluoroacetic acid (TFA); and by gradient elution using a 2012 proposed horizontal developing chamber for stepwise gradient elution in reversed-phase mode, with different concentrations of methanol and buffer (pH=3.0, 3 mM citric acid and 1.5 mM disodium hydrogen phosphate in deionized water). When the citrate buffer was replaced by TFA the front of the mobile phase was more uniform and the phenomenon of flow of the mobile phase to the surface of the adsorbent layer was not observed; therefore, the substance zone was well shaped. The best gradient separation was obtained with a 4-step convex gradient: the concentrations of methanol in subsequent fractions of the mobile phase were 40, 60, 70, and 80 % (v/v) and the migration distances of the fractions were 10, 10, 20 and 30 mm, respectively. The total development distance was 70 mm. The results showed high repeatability within the same plate and between studies. The highest values of precision (%RSD >2 %) were obtained for the most strongly retained substances (oil red, dye No. 8, and fat green, dye No. 2).

Food Chem. 242, 601-610 (2018). Review of recent research on L-theanine, including the use of HPTLC for the rapid quantitative determination in Camellia sinensis and the combination with other non-chromatographic techniques.

CBS 119 (2017) 14-15. HPTLC of Cannabis sativa and standards cannabidiol (CBD), tetrahydrocannabinol (THC), and cannabinol (CBN) on silica gel with n-heptane – diethyl ether – formic acid 75:25:0.3 with chamber saturation for 20 min to a migration distance of 70 mm. Detection by spraying with Fast Blue salt B reagent (250 mg o-dianisidine bis(diazotized) zinc double salt in 10 mL water, 25 mL methanol and 15 mL dichloromethane), evaluation under white light. Quantitative determination by absorbance measurement at 210 nm prior to derivatization (for cannabinoid acids 285 nm). For the screening of THC-free samples the limit test can be used. The EU limit of 0.2 % is easily detected with or without detection. The %RSD of the assay prior to derivatization is 1.5 % and after derivatization 2.1 %. The LOD is 10 ng/zone.

J. Chromatogr. Sci. 55 (10), 1059-1065 (2017). Presentation of a new high-throughput method for the simultaneous analysis of isoflavones and soyasaponins in soy (Glycine max L.) products by HPTLC on silica gel with ethyl acetate – methanol – water – acetic acid 100:20:16:1. Detection by treatment with anisaldehyde sulfuric acid reagent. Quantitative determination by densitometric multi-wavelength scanning at UV 265 nm for genistin, daidzin and glycitin and at 650 nm for soyasaponins I and III. The correlation coefficient of the linear calibration curve was >0.994. Intra-day precision (%RSD) of substances in matrix was between 0.7-0.9 %, inter-day precision (%RSD) was between 1.2-1.8 %). The method was suitable for the determination of the studied analytes in soy-based infant formula and soybean products.

J. Planar Chromatogr. 31, 250-256 (2018). HPTLC of fifteen 17β-carboxamide glucocorticoid derivatives and prednisolone on RP-18 with acetonitrile – water (1:1, 3:2, 7:3, and 4:1), acetone – water (1:1, 3:2, 7:3, and 4:1, and 9:1), ethanol 96 % – water (1:1, 3:2, 7:3, and 4:1), methanol – water (3:2, 7:3, 4:1, and 9:1) and tetrahydrofuran – water (1:1, 3:2, 7:3, and 4:1). The system consisting of water and ethanol 96 % was selected as the most suitable for the prediction of octanol – water partition coefficients (log Po/w).

Separations 5, 1-11 (2018). HPTLC of lipid content in yeast (clonal prion-infected and prion-free cells) on silica gel with 1) petroleum ether – diethyl ether – glacial acetic acid 80:20:1 for free sterols, free fatty acids, and triacylglycerols, 2) hexane – petroleum ether – diethyl ether – glacial acetic acid 50:20:5:1 for steryl esters, methyl esters, and squalene and 3) chloroform – diethyl ether – acetic acid 130:50:9 for phospholipids (phosphatidylethanolamine, phosphatidylcholine, and phosphatidylinositol). Detection of neutral lipids by spraying with 5 % phosphomolybdic acid in ethanol, followed by heating at 120 °C for 30 min. Detection of phospholipids by spraying with 10 % cupric sulfate in 8 % phosphoric acid, followed by heating at 140 °C for 30 min. Evaluation at 370 nm (deuterium lamp) for phospholipids and at 610 nm (halogen-tungsten lamp) for neutral lipids. The hRf values for neutral lipids were 10 for cholesterol, 33 for oleic acid and 51 for triolein as well as 41 for methyl oleate, 56 for cholesteryl oleate and 77 for squalene. The hRf values of phospholipids were 21 for phosphatidylinositol, 27 for phosphatidylethanolamine and 48 for phosphatidylcholine. HPTLC demonstrated to be a powerful tool for revealing subtle changes in the physiology of yeast.