J. AOAC Int. 93, 804-810 (2010). HPTLC of rutin on amino phase with ethyl acetate - formic acid - methanol - water 100:9:11:17 at room temperature. Detection by spraying with natural products reagent. Linearity was between 0.95 and 4.78 µg/zone. LOD and LOQ were 330 and 630 ng/zone, respectively. The %RSD for six replicates at three concentration levels was less than 3 %, while the recovery was between 97.3-103.3 %. For the three-dimensional image analysis of chromatograms images were taken from each plate using a HP flatbed scanner at an optical resolution of 300 dpi in normal mode. The pictures were stored in TIFF file format. Evaluation was performed using Melanie 7.0 software. Following automatic detection of the zones the program computed the 3D image of a selected region from the HPTLC plate. The volume of the resulting cone-shaped zone was used as numerical data to construct the calibration curve.

J. Ethnopharmacol. 160, 164-172 (2015). HPTLC of quercetin in methanolic extracts of aerial parts of Tricholepis glaberrima on silica gel (prewashed with methanol and activated at 110 °C for 10 min) with toluene - ethyl acetate - formic acid 25:20:1. Quantitative determination by absorbance measurement at 280 nm. The hRF value of quercetin was 48.

J. Planar Chromatogr. 28, 300-306 (2015). HPTLC of ellagic acid (1), gallic acid (2) and methyl gallate (3) in gall of Quercus infectoria on silica gel with toluene - ethyl acetate - formic acid 12:9:4. Quantitative determination by absorbance measurement at 300 nm. The hRF values for (1) to (3) were 19, 29 and 46, respectively. Linearity was in the range of 590-1181 ng/zone for (1), 691-2114 ng/zone for (2) and 693-2078 ng/zone for (3). LOD and LOQ were 15 and 51 ng/zone for (1), 243 and 812 ng/zone for (2) and 155 and 516 ng/zone for (3), respectively. The intermediate precision was 3.5 % (n=3). Recoveries ranged between 96 and 102 % for (1), 97 and 105 % for (2) and 95 and 97 % for (3).

J. Ethnopharmacol. 192, 283-291 (2016). Ubtan is a traditional herbal formulation in the Indian system of medicine, prepared by mixing powdered turmeric (Curcuma longa L.), chickpea (Cicer arietinum L.) and sandal wood (Santalum album L.). HPTLC of four in-house formulations of Ubtan (UF-1, UF-2, UF-3 and UF-4, prepared with varying quantities of each ingredient) on silica gel with cyclohexane – ethyl acetate – formic acid 90:9:1. Detection by spraying with p-anisaldehyde sulfuric acid reagent, followed by drying at 40 ºC for 10 min. The hRF values for UF-1 were 70 and 42.

CBS 118, 5-7 (2017). Presentation of two HPTLC methods for 1) detection and identification of UV filter substances in suncream and 2) detection of phenolic markers in Edelweiss species (Leontopodium spp.). For 1) HPTLC of sun cream samples and standards octocrylene, avobenzone, octisalate and ensulizole on silica gel first with heptane – ethyl acetate 4:1 with chamber saturation, migration distance 70 mm, then with isopropanol, without saturation, migration distance 28 mm. Densitometric evaluation by absorbance measurement at UV 254 nm. Direct elution of target zones into a single quadrupole MS, detection in positive and negative ionization mode. For 2) HPTLC of methanolic and glycerol-based Edelweiss extracts and standards chlorogenic acid, apigenin, luteolin, luteolin-4-O-glucoside, luteoline-7-O-glucoside, leontopodic acids A and B, cynarine, and 3,5-dicaffeoylquinic acid on silica gel with butyl acetate – formic acid – water 280:100:3 with chamber saturation, migration distance 70 mm. Detection by heating the plate at 100 °C for 3 min and immersing (while still hot) into natural products reagent (1 g of 2-aminoethyl diphenylborinate in 200 mL ethyl acetate). Evaluation under UV 366 nm.

Planta Medica 83(14/15), 1200-1206 (2017). The fractionation on cyclodextrane with methanol of the butanol-soluble parts of a methanolic macerate of Gymnocarpos decander aerial parts was monitored by TLC on silica gel with n-butanol – acetic acid – water 12:3:5. Detection by derivatization with cerium sulfate–sulfuric acid reagent. Through further analysis of the 5 resulting fractions, roseoside and heterosides of quercetin, of isorhamnetin and of tetrahydroxyoleanene were detected._x000D_

J. Chromatogr. 315, 101-109 (1984). TLC of naturally occurring flavone aglycones on silica with benzene - methanol - acetic acid 45:3:2 or with chloroform - hexane - methanol 40:40:3. AIso TLC of permethylated flavones on silica with chloroform - ethyl acetate - acetone 5:4:1, butanol-hexane 15:85 or benzeneethyl acetate 6:4. Detection by UV 366 nm. The 5-hydroxy-flavones with methoxy groups at 6 or 8 showed dark purple colors. Rf values of 16 5-hydroxy-flavones. In general, 6-methoxyflavones showed higher Rf values than the corresponding 8-methoxy compounds.

Biochemical Systematics and Ecology 14, 291-298 (1986). TLC study of the flavonoid quantities of individual red oak leaves grown in the sun and shade. Separation of isohamnetin, kaempferol, myricetin and quercetin on silica with a) chloroform - iso-propanol - MEK - acetic acid 10:3:3:4 and b) water - butanol - dioxane -acetone 42:9:4:7.