Planta Med. 83, 1011-1019 (2017). The subfractionation on silica gel column of a diethyl ether fraction of a hydromethanolic extract of Lamium album aerial parts was controlled by TLC on silica gel with ethyl acetate – formic acid – water 20:2:3. Detection was performed at UV light after derivatization with 1 % Natural Product Reagent A. From the last subfraction, caffeic acid and tiliroside were isolated. The same TLC monitoring was applied for the fractionation of the butanol fraction of the extract. Some fractions and their subfractions were purified on dextran gel (Sephadex LH-20), and monitored by TLC on silica gel with ethyl acetate – formic acid – acetic acid – water 100:11:11:26, with the same detection. These subfractions contained caryoptoside and other iridoids, glucomartynoside, lamiusides and other phenylpropanoid derivatives.

J. Planar Chromatogr. 31, 143-149 (2018). HPTLC of stigmasterol (1), β-sitosterol (2), campesterol (3) and ergosterol (4) in Heteropogon contortus on silica gel with toluene – methanol – formic acid 90:10:3. Detection by spraying with anisaldehyde sulfuric acid followed by heating at 110-120 °C for 4-5 min. Quantitative determination by absorbance measurement at 530 nm. The hRf values for (1) to (4) were 23, 13, 39 and 28, respectively. Linearity was in the range of 2-12 ng/zone for (1) to (4). The LOD and LOQ were 50 and 200 pg/zone for (1), 13 and 40 pg/zone for (2), 86 and 260 pg/zone for (3) and 20 and 60 pg/zone for (4), respectively. Recovery was in the range of 98.4 and 99.6 % for (1) to (4).

J. Chromatogr. Sci. 55 (5), 571-577 (2017). Proposal of a rapid, easy and efficient method for calcium oxalate crystal inhibition in the agar gel system analogous to antimicrobial well diffusion assay, and TLC-agar-overlay bioautography (note that the term "direct bioautography" is wrongly used in the title) to detect the antilithiatic metabolites and to localize the active metabolites in Phyllanthus niruri, an Ayurvedic plant. The agar well diffusion method showed 50 % inhibitory concentration (IC50) value at 229 and 494 mg/mL for tri-sodium citrate and Phyllanthus niruri extract, respectively, with the lowest concentration showing visible crystal inhibition (minimum inhibitory concentration, MIC) of 20 mg/mL in both samples. With this method the successful screening, detection and confirmation of calcium oxalate crystal inhibitory metabolites from P. niruri was possible. Detection of tuberonic acid in the bioactive fraction of P. niruri by HPLC-HRMS.

J. Planar Chromatogr. 31, 429-436 (2018). HPTLC of _x000D_caffeic acid (1), ferulic acid (2), β-sitosterol (3), and lupeol (4) on silica gel with toluene – ethyl acetate – formic acid 85:15:1. Quantitative determination by absorbance measurement at 366 nm for (1) and (2) and 580 nm for (3) and (4). The hRF values for (1) to (4) were 14, 29, 48 and 63, respectively. Linearity ranged between 100-600 ng/zone for (1) and (2) and 200-700 ng/zone for (3) and (4). LOD and LOQ were 49 and 149 ng/zone for (1), 93 and 282 ng/zone for (2), 194 and 589 ng/zone for (3) and 36 and 109 ng/zone for (4), respectively. The intermediate precision was <2 % (n=6). Average recovery was 99.6 % for (1), 99.9 % for (2), 99.2 % for (3) and 99.5 % for (4).

J. Planar Chromatogr. 31, 332-336 (2018). HPTLC of β-sitosterol (1) and lupeol (2) in Saussurea lappa and Saussurea auriculata on silica gel with toluene ‒ ethyl acetate ‒ glacial acetic acid 29:9:2. Detection by spraying with anisaldehyde–sulfuric acid reagent. Quantitative determination by absorbance measurement at 525 nm. The hRf values for (1) and (2) were 71 and 88, respectively. Linearity was between 100 and 400 ng/zone. LOD and LOQ were 7 and 23 ng for (1), and 6 and 17 ng for (2), respectively. The intermediate precision was <2 %. Average recovery was 99.9 % for (1) and 100.0 % for (2).

J. Planar Chromatogr. 31, 280-289 (2018). HPTLC of prilocaine (1), lidocaine (2), O-toluidine (3) and 2,6-dimethylaniline (4) on silica gel with toluene – chloroform – ethanol – triethylamine 50:50:10:1. The hRf values for (1) to (4) were 27, 37, 58 and 67, respectively. Quantitative determination by absorbance measurement at 220 nm. Linearity ranged between 0.4-9.0 μg/zone for (1), 0.8-11.0 μg/zone for (2), 0.2-2.9 μg/zone for (3) and 0.1-1.4 μg/zone for (4). LOD and LOQ were 1.5 and 4.4 μg/mL for (1), 5.1 and 15.5 μg/mL for (2), 1.3 and 4.1 μg/mL for (3) and 1.0 and 3.1 μg/mL for (4). The intermediate precision was <1 % (n=3). Average recovery was 100.3 % for (1), 100.9 % for (2), 99.8 % for (3) and 100.3 % for (4).

Lipids 17, 107-110 (1982). TLC of glycolipids (glucocerebromide, lactosyl ceramide, globotriosyl ceramide, gangliotriosyl ceramide, globoside I, asialo-GM1) on silica with chloroform methanol - 0.2 % aq. CaCl2 55:45:10. Detection with anthrone-sulfuric acid reagent.

Budapest Chromatography Symposium June 13, 1985. Preparative isolation of pure coumarins and furocoumarins by TLC on silica, including two-dimensional separation with 1) 3 % isopropyl ether in dichloromethane - heptane 7:3 and 2) 10 % isopropyl ether in dichloromethane -heptane 3:7.