Planta Medica 84(1), 26-33 (2018). For the monitoring of the multi-step fractionation through VLC (vacuum liquid chromatography) of the chloroform-soluble parts of a methanol – water 7:3 percolate of Hippophae rhamnoides (Eleagnaceae) fruit peels, TLC on silica gel and RP-18, detection by spraying with sulfuric acid and heating. Preparative TLC on silica gel with cyclohexane – dichloromethane – methanol 5:15:1 to isolate, from VLC subfractions, three lignans (nectandrin B, fragransin A2, saucernetindiol) that are diastereoisomers of each other.

J. Planar Chromatogr. 32, 447-451 (2019). HPTLC of Fritillaria cirrhosa on silica gel with ethyl acetate - methanol - ammonia solution - water 180:20:10:1. Bioautography by dipping into a 0.15 mg/mL solution of substrate Gly-Pro-p-nitroanilide hydrochloride in 50 % of ethanol, followed by ethanol removal in the hood and dipping into a 10 U/L DPP IV enzyme solution in TrisHCl buffer (pH 8.2, 70 mM), followed by incubation at 37°C for 40 min. Detection by dipping into a solution of 0.5 % sodium nitrite in 1.2 M hydrochloric acid, followed by drying slightly for 5 min and dipping into 0.05 % N-(1-naphthyl)ethylenediamine dihydrochloride solution. Further analysis by mass spectrometry using a TLC interface. The hRF value for the dipeptidyl peptidase IV inhibitor was 58.

J. Ethnopharmacol. 235, 361-374 (2019). HPTLC of colchicine (1) and withaferin A (2) in the polyherbal ayurvedic formulation Peedantak Vati (PV) on silica gel with chloroform - 
methanol - water - formic acid 140:13:2:4. Quantitative determination by absorbance measurement at 218 nm. The hRF values for (1) and (2) were 22 and 28, respectively. LOD and LOQ were 40 and 120 ng/zone for (1) and 120 and 240 ng/zone for (2), respectively.  

J. AOAC Int. 102, 726-733 (2019). HPTLC of different parts of Alpinia offcinarum on silica gel with n-hexane - ethyl acetate - acetic acid 6:1:1. Antioxidant activity analysis by spraying with methanolic 0.04 % 2,2-diphenyl-1-picrylhydrazyl (DPPH*) radical reagent, followed by densitometric detection at 535 nm. Zones were scraped from HPTLC plates and further analyzed by electrospray ionization quadrupole time-of-flight tandem mass spectrometry (ESI-Q-TOF-MS/MS). The method allowed the identification of three antioxidant compounds: (5R-hydroxy-7-(4-hydroxy-3-methoxyphenyl)-1-phenyl-3-heptanone, kaempferide, and galangal with hRF values of 21, 33 and 40, respectively.

J. Planar Chromatogr. 32, 41-46 (2019). HPTLC of ayapanin in the leaves of Ayapana triplinervis on silica gel with ether - ethyl acetate 3:2. Quantitative determination by absorbance measurement at 254 nm. The hRF value of ayapanin was 56. Linearity was between 200 and 1000 ng/zone. The intermediate precision was below 0.8 % (n=6). The LOD and LOQ for ayapanin were 54 and 169 ng/zone, respectively. Recovery rate was 99.7 % for ayapanin.

J. Planar Chromatogr. 21, 83-88 (2008). TLC of (+)-catechin and (-)-epicatechin on silica gel with diisopropyl ether - formic acid 9:1 in an unsaturated twin-trough chamber. Detection by spraying with vanillin-sulfuric acid reagent followed by heating at 120 °C for 5 min. Quantitative determination by absorbance measurement at 490 nm.

CBS 107, 13-15 (2011). HPTLC of 5-hydroxymethylfurfural (HMF) in honey on silica gel, prewashed with methanol - water 6:1, with ethyl acetate. Quantitative determination by densitometry in absorbance mode at 290 nm. Optional detection by immersion in p-aminobenzoic acid reagent followed by heating at 110 °C for 5-10 min. The hRf value of HMF was 80. The calibration function was polynomial in the range of 0.8-80 ng/band whilst Michaelis Menten 2 regression was suitable for higher concentrations. The LOD of HMF in honey samples was 0.75 mg/kg (12 µL applied) and the LOQ 2.4 mg/kg. The method complies with the requirement of max. 15 mg/kg of HMF in honey. The results with this method were compared with those obtained by the spectrophotometric Winkler method and by HPLC-UV and mean differences were minor (3.3 % or 0.9 mg/kg). Complementary confirmation by HPTLC-MS online coupling. HMF zones identified under UV were eluted and analyzed by ESI-MS in full-scan and SIM mode.

by principal component analysis. J. Planar Chromatogr. 28, 274-279 (2015). DPPH-HPTLC bioautography assay of Hibiscus sabdariffa on silica gel with toluene - ethyl acetate - formic acid - methanol 30:30:8:5. Analysis by dipping into 0.05 % DPPH methanolic solution. Combination with liquid chromatography-quadrupole time-of-flight mass spectrometry enabled the rapid screening and identification of the antioxidants in Hibiscus sabdariffa.