J. Planar Chromatogr. 30, 193-198 (2017). HPTLC of 20-hydroxyecdysone in Sesuvium portulacastrum on silica gel with chloroform – methanol – benzene 25:5:3. Quantitative determination by absorbance measurement at 254 nm. The hRF value for 20-hydroxyecdysone was 30. Linearity was between 50 and 500 ng/zone. LOD and LOQ were 4 and 14 ng/zone. The intermediate precision was below 2 % (n=6). The recovery rate ranged from 98.6 to 102.4 %.

J. Chromatogr. Sci. 54 (8), 1421-1427 (2016). Development of a simple, cost-effective and reliable method for quantification of naphthoquinones, found as natural red color pigments in roots of Arnebia benthamii (Wall. ex G.Don) I.M. Johnst., by HPTLC on silica gel with hexane – ethyl acetate – methanol 16:3:1. Determination of shikonin (hRf 37) and β,β-dimethylacryl shikonin (hRf 58) in the methanol extract by densitometry at 520 nm. The linearity was 0.1-8 µg/zone. The average recovery was >97 % for both and the intraday and interday precision for the quantification of naphthoquinones was good (%RSD <2.0 %). The LOD were 13 and 15 ng/zone for shikonin and β,β-dimethylacryl shikon and the LOQ were 39 and 44 ng/zone, respectively.

J. Liq. Chromatogr. Relat. Technol. 40, 725-731 (2017). HPTLC of butylated hydroxytoluene (BHT) in Antarctic krill on silica gel with petroleum ether – ethyl acetate – hexane 8:2:1. Detection by spraying with 5 % aqueous ferric chloride followed by heating at 105 °C for 5-10 min. Quantitative determination by absorbance measurement at 600 nm. The hRF value for BHT was 79. Average recovery was 101.8 %.

J. Planar Chromatogr. 31, 213-219 (2018). HPTLC of β-sitosterol in the leaves of five Ficus species (F. carica, F. nitida, F. ingens, F. palmata, and F. vasta) on silica gel with ethyl – acetate 4:1. Detection by spraying with p-anisaldehyde reagent followed by drying. Quantitative determination by absorbance measurement at 550 nm. The hRf value for β-sitosterol was 17. Linearity was in the range of 100-1400 ng/zone. The intermediate precision was below 2 % (n=6). The LOD and LOQ were 32 and 98 ng/zone, respectively. Recovery was between 98.5 and 99.7 %.

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.

Phytochemistry 157, 92-102 (2019). HPTLC of monogalactosyldiacylglycerol (1) and digalactosyldiacylglycerol (2) in the leaves of basket willow (Salix viminalis L., Salicaceae, Malpighiales), cabbage (Brassica oleracea L., Brassicaceae, Brassicales), pea (Pisum sativum, Fabaceae, Fabales), roseroot (Rhodiola rosea L., Crassulaceae, Saxifragales), meadow buttercup (R. acris L., Ranunculales), garlic (Allium sativum L., Amaryllidaceae, Asparagales) and Ipomoea tricolor Cav. (Convolvulaceae, Solanales) on silica gel with acetone – benzene – water 91:30:8. Qualitative identification under UV light at 254 and 366 nm. The hRF values were 20-26 for (1) and 63-77 for (2).

Braz. J. Pharmacog. 28, 631-639 (2018). HPTLC of 3-O-α-L-rhamnopyranosyl-(1→ 2)-α-L-arabinopyranosyl pomolic acid, 2,4,6-trihydroxy-4-methoxybenzophenone-2-O-β-d-glucoside, hyperoside, geniposidic acid, nicotiflorin, narcissin, randiasaponin IV and rutin in the leaves, stems and roots of Fadogia agrestis on silica gel with chloroform – ethyl acetate – methanol – formic acid 15:30:10:4. Detection by immersion in the anisaldehyde–sulfuric acid reagent, followed by heating at 100 ºC for 3 min. The HPTLC fingerprinting method was suitable for rapid decisive authentication and comparison of differences among samples of identical source.

Pharmacogn. Mag. 14, 377-383 (2018). HPTLC fingerprinting of Cichorium intybus seeds on silica gel with toluene – ethyl acetate – formic acid 3:4:1. The fingerprint was recorded under UV light at 254 and 366 nm.