J. AOAC Int. 99, 374-379 (2016). HPTLC of glabridin in the roots of Glycyrrhiza glabra on silica gel with hexane – ethyl acetate – chloroform 5:4:3. Quantitative determination by absorbance measurement at 285 nm. The hRF value of glabridin was 48. Linearity was in the range of 50-500 ng/zone. The LOD and LOQ were 10 ng/zone and 30 ng/zone, respectively. Intermediate precisions were below 2 %. Recovery was between 100.6 and 102.0 %. Compared to a validated HPLC method there was no statistically significant difference in the mean values.

J. Ethnopharmacol. 197, 242-249 (2017). Kanakasava is an Indian traditional Ayurvedic formulation containing Datura metel, Adhatoda vasica, Woodfordia fruticosa and Vitis vinifera extracts as major constituents. HPTLC of gallic acid (1) and ethyl gallate (2) on silica gel with toluene – ethyl acetate – formic acid – methanol 35:35:8:5. Quantitative determination by absorbance measurement at 292 nm. The hRF values for (1) and (2) were 43 and 48, respectively.

J. Liq. Chromatogr. Relat. Technol. 41, 329-341 (2018). HPTLC of flavonoids (flavone, apigenin, luteolin, chrysin, quercetin dihydrate, myricetin, kaempferide, kaempferol, naringenin and pinocembrin) in propolis, roasted coffee, rose hip, hibiscus, rosemary and sage on silica gel with n-hexane – ethyl acetate – formic acid 20:19:1. Detection by heating the plate at 110 ºC for 3 min, followed by dipping into NP reagent (1 g of diphenylboric acid 2-aminoethyl ester in 200 mL of ethyl acetate) for 1 s, and after drying into paraffin – n-hexane 1:2 or PEG 4000 for 1 s (for enhancement and stabilization of fluorescent zones), followed by drying for 2 min. Qualitative identification under UV 254 and 366 nm. HPTLC–MS(/MS) analysis was also performed using a TLC-MS interface. Some possible interferences with phenolic acids (chlorogenic acid, rosmarinic acid, protocatechuic acid, gallic acid, syringic acid, ellagic acid, trans-cinnamic acid, o-coumaric acid, m-coumaric acid, p-coumaric acid, caffeic acid, ferulic acid, sinapic acid) were also examined.

Anders. J. Planar Chromatogr. 31, 437-443 (2018). HPTLC of apigenin (1) and luteolin (2) in Hygrophila spinosa on silica gel with toluene – ethyl acetate – formic acid 6:4:1. Quantitative determination by absorbance measurement at 349 nm. The hRF values for (1) and (2) were 64 and 54, respectively. Linearity ranged between 80-560 ng/zone for (1) and 40-280 ng/zone for (2). LOD and LOQ were 6 and 19 ng/zone for (1) and 2 and 7 ng/zone for (2), respectively. The intermediate precision was <3 % (n=3). Recovery was between 99.3 and 100.5 % for (1) and 99.5 and 100.8 % for (2).

Nanjing Med. College (Nanjing Yaoxueyuan Xuebao) 4, 14-16 (1965). (Chinese) (Thin-layer densitometry of hesperidin in citrus cortices and its powdered preparation with snake bile.) TLC of hesperidin on silica with butanol - acetic acid - water 4:1:1. Quantification by densitometry.

J. Chromatogr. 403, 285-287 (1987). Presentation of a spray reagent, chlorosulphonic acid - chloroform 4:1, for the detection of coumarins and flavonoids on silica. Detection limits, less than 1 µg for most of the 28 test compounds.

Biochemical Systematics and Ecology 15, 529-530 (1987). Two dimensional TLC of C-glycosyl-flavones, shaftoside and isoshaftoside on cellulose with tert.-butanol and 15% acetic acid.

Planta Med. 55, 73-74 (1989). TLC of quercetin and isorhamnetin on silica with benzene - methanol - acetic acid 45:8:4. TLC of glucose and rhamnose on silica with butanol - acetic acid - water 4:1:5 and isopropanol - boric acid 85:15. Detection of flavonoids under UV 366 nm and by spraying with 1% AlCl3 in methanol followed by heating at 100°C for 5 min. Visualization of sugars with aniline hydrogenphthalate followed by heating at 110 °C for 10 min.