Planta Medica 84(2), 129-134 (2018). TLC of subfractions obtained from normal-phase LC and size-exclusion chromatography of an ethanolic extract of Bougainvillea spectabilis (Nyctaginaceae) stem-bark on RP-18 with methanol – water 2:3 and 1:1 to isolate six flavones (bougainvinones J, K, L, M, and two dimethylflavone derivatives).

Planta Medica 84(1), 59-64 (2018). A multi-step fractionation through silica gel column chromatography (CC) of a methanolic extract of Plectranthus africanus (whole plant, Lamiaceae) was monitored through TLC on silica gel with various solvent mixtures (n-hexane or dichloromethane with either acetone or methanol). Zones were detected under UV and further by spraying with sulfuric acid 20 % and heating at 100°C. For each fraction or TLC profile, the authors provide the CC gradient, the optimal proportions of the solvents used for the TLC mobile phase, as well as the RF values of the molecules isolated by this CC method: new abietane-type diterpenoids (plectranthroyleanones A, B, C), betulinic and oleanolic acids, heterosides of apigenin, rhamnetin and sitosterol.

J. Liq. Chromatogr. Relat. Technol. 42, 563-569 (2019). HPTLC of spinosin in the fruits of Ziziphus jujuba on silica gel with ethyl acetate - dichloromethane - methanol - water 18:10:15:5. Quantitative determination by absorbance measurement at 334 nm. The hRF value for spinosin was 38. Linearity was between 10 and 120 ng/mL. Intermediate precision was below 2 % (n=6). The LOD and LOQ were 12 and 35 ng/mL, respectively. Recovery rate was between 98.7 and 101.3 %. The HPTLC method provided similar reproducibility, accuracy and selectivity for the quantitative determination of spinosin compared with a HPLC method.

J. AOAC Int. 102, 1003-1013 (2019). HPTLC of quercetin (1) and berberine (2) in Pushyanuga Churna on silica gel with toluene - ethyl acetate - methanol - formic acid 6:6:2:1. Quantitative determination by absorbance measurement at 254 nm for (1) and 366 nm for (2). The hRF values for (1) and (2) were 63 and 24, respectively. Intermediate precisions were below 2 % (n=3). The LOD and LOQ were 1 and 3 µg/mL for (1) and 0.05 and 0.1 µg/mL for (2), respectively. Recovery rate was between 93.5 and 100.6 % for (1) and 95.2 and 97.6 % for (2).

J. Planar Chromatogr. 32, 467-474 (2019). HPTLC of quercetin in the fresh fruits of Benincasa hispida on silica gel with toluene - ethyl acetate - formic acid 25:20:1. Quantitative determination by absorbance measurement at 262 nm. The hRF value for quercetin was 39. Linearity was between 100 and 1200 ng/zone. Intermediate precision was below 2 % (n=6). The LOD and LOQ were 20 and 60 ng/zone. Recovery rate was 94.3 %.

J. Planar Chromatogr. 32, 393-400 (2019). HPTLC of quercetin (1) and resveratrol (2) on silica gel with toluene - ethyl acetate - formic acid 12:5:3. Quantitative determination by absorbance measurement at 286 nm. The hRF values for (1) and (2) were 41 and 46, respectively. Linearity was between 50 and 2000 ng/zone for both (1) and (2).  Intermediate precision was below 2 % (n=3). The LOD and LOQ were 27 and 122 ng/zone for (1) and 83 and 370 ng/zone for (2), respectively. Recovery rate was between 99.6 and 101.9 % for (1) and (2).

J. Planar Chromatogr. 32, 371-377 (2019). HPTLC of rutin in the fruits of Benincasa hispida on silica gel with ethyl acetate - formic acid - acetic acid - water 72:7:7:14. Quantitative determination by absorbance measurement at 268 nm. The hRF value for rutin was 36. Linearity was between 0.6 and 2.7 µg/zone. Interday and intra-day precisions were below 2 % (n=6). The LOD and LOQ were 0.1 and 0.3 µg/zone. Recovery rate was 96 %.

J. Sep. Sci. 42, 1088-1104 (2019). TLC of vicenin-2, schaftoside, isoschaftoside, isoviolanthin, apigenin-6-C-β-D-xyloside-8-C-α-L- arabinoside and rutin in Dendrobium huoshanense on silica gel with ethanol - acetic acid - butanone - acetone - water 22:10:13:5:65. Qualitative identification under UV light at 366 nm.