J. Ethnopharmacol. 195, 10-19 (2017). HPTLC of mesembrine alkaloids (mesembrine, mesembrenone, mesembrinol, mesembrenol, epimesembranol, epimesembrenol) in the South African medicinal plant Sceletium tortuosum on silica gel with dichloromethane – methanol – 10 % ammonia 900:100:1. Quantitative determination by absorbance measurement at 280 nm. The LOD and LOQ were in the range of 18-31 ng/zone and 44-95 ng/zone, respectively.

J. Planar Chromatogr. 29, 474-476 (2016). HPTLC of methamphetamine in Ya-Ba tablets on silica gel with methanol ‒ ammonium 200:3. Quantitative determination by absorbance measurement at 259 nm. The hRF value was 35. Linearity was between 600 and 3000 μg/zone. The intermediate precision was 11.2 % (n=3). The LOD and LOQ were 153 and 463 μg/zone, respectively. Average recovery was 102.3 %.

J. Planar Chromatogr. 30, 219-224 (2017). HPTLC of 18 derivatives obtained by substitution of chlorine atom at C7 or/and C6 in 6,7-dichloro-5,8-quinolinedione on RP-18 with a mixture of acetone and _x000D_water solution of buffer Tris (pH 7.4) in different volume compositions ranged from 30 % to 85 % in 5 % increments. The correlation between experimental and calculated values of lipophilicity was analyzed.

J. Chromatogr. A 1465, 197-204 (2016). Demonstration of a strategy for an improved quality control of propolis shown on the example of 30 French propolis samples based on evaluation of their HPTLC fingerprints in combination with selected mass signals obtained by desorption-based scanning mass spectrometry (MS). Separation of the French propolis sample extracts by HPTLC on silica gel with n-hexane – ethyl acetate - acetic acid 5:3:1 and on RP phase with n-hexane – toluene – ethyl acetate – formic acid – acetic acid 16:6:10:3:3, both in twin-trough chambers with 37 % hydrochloric acid applied on a filter paper in the second trough of the chamber. Analysis of the fingerprints, obtained by two different detection modes, i.e. after (1) derivatization with NP and PEG reagents and fluorescence detection at UV 366 nm and (2) scanning direct analysis in real time (DART)-MS, by multivariate data analysis. The best classification was obtained using both methods, RP-HPTLC-FLD and RP-HPTLC-DART-MS, in combination with pattern recognition techniques, such as principal component analysis. Observation of the characteristic patterns from the two types, in which all investigated French propolis samples were divided. Identification of phenolic compounds, such as caffeic acid, p-coumaric acid, chrysin, pinobanksin, pinobanksin-3-acetate, galangin, kaempferol, tectochrysin and pinocembrin, as characteristic marker compounds of French propolis samples. Confirmation of the presence of two botanically different types of propolis, known as the blue and orange types.

J. Planar Chromatogr. 30, 136-141 (2017). 2D-HPTLC of estrone (1), estradiol (2), 17α-ethinylestradiol (3), estriol (4), bisphenol A (5), trans-resveratrol (6), zearalenone (7), and diethylstilbestrol (8) on RP-18W with hexane – ethyl acetate – acetone 11:3:2 in the first direction and acetone – water 3:2 in the second direction. Detection by heating at 110 °C for 10 min, followed by dipping into a mixture of sulfuric acid - water 1:49 for 1 s and heating again at 110 °C for 10 min. Quantitative determination under UV light at 366 nm. The hRf values in the first/second direction for (1) to (8) were 52/27, 36/27, 45/24, 6/44, 41/31, 51/17, 49/22 and 17/47, respectively. 17α-ethinylestradiol was quantified in an effect-directed analysis using the yeast strain S. cerevisiae BJ3505. The activation of the estrogen receptor by estrogen active compounds was measured by inducing the reporter gene lacZ which encodes the enzyme ß-galactosidase. The enzyme activity was determined directly on TLC plate by using the fluorescent substrate MUG (4-methylumbelliferyl ß-D-galactopyranoside). The LOD and LOQ were 31 and 57 pg/zone, respectively.

J. Liq. Chromatogr. Relat. Technol. 40, 22-286 (2017). HPTLC of clarithromycin (1), azithromycin (2), and amodiaquine (3) and artesunate (4) on silica gel with methanol – ethyl acetate – concentrated ammonium hydroxide 40:10:1 for (1) and (2) and acetone – water – concentrated ammonium hydroxide 40:7:2 for (3) and (4). Detection by heating for 15 and 30 min, respectively, for (1) and (2) at 160 °C to activate fluorescence quenching. Naturally fluorescence quenching zones of (3) were scanned at 254 nm and (4) after heating the plate for 5 min at 180 °C to activate fluorescence quenching.

J. Chromatogr. Sci. 54 (4), 609-617 (2016). HPTLC of sulbutiamine (SUL) in the presence of different degradation products after subjecting the drug to stress conditions (according to ICH: neutral, alkaline and acidic hydrolysis, oxidation, photodegradation and dry heat degradation), on silica gel aluminum foil with acetone – methylene chloride – ammonia buffer (pH 8.5±0.2) 14:6:1. Densitometric evaluation at 254 nm. The calibration curve was between 0.4–5.0 µg/zone with good correlation coefficients. The LOD and LOQ were 110 and 330 ng/zone, respectively. Structure elucidation of the resulting degradation products by ESI-MS/MS. The results showed that the drug was completely degraded with 0.1 N NaOH, 1 N HCl and 30 % hydrogen peroxide, while it was partially degraded by 0.1 N HCl, 3 % hydrogen peroxide and UV light. The hRf of SUL was 46 and the zone was completely separated from all obtained degradation products.

J. Ethnopharmacol. 213, 230-255 (2018). Review of the botany, ethnopharmacology, phytochemistry, biological activities, nutritional value, possible molecular mechanisms, safety and clinical applications of Morinda officinalis with a special focus on its bioactivities, including the application of HPTLC for the analysis of oligosaccharides from different habitats.