Nature - Lab. Invest. 100, 1411–1424 (2020). Samples were chloroform – methanol 1:1 solutions of lipid standards and of liver tissue extracts from wild-type mice (1), from transgenic murine models of hepatic steatosis (2) (mice expressing HBs, hepatitis B virus surface protein), or of cholestasis (3) (mice totally knock-out for the gene of phospholipid translocator ABCB4, ATP-binding cassette subfamily B member 4), or of both (4) (hybrids of mice (2) and (3)). HPTLC on silica gel (preheated at 110°C for 15 min) with n-hexane – diethyl ether – acetic acid 20:5:1. (A) For qualitative analysis, visualization under white light after immersion into anisaldehyde 0.5 % (in sulfuric acid – acetic acid – methanol, 1:2:17), followed by heating at 110°C for 9 min. (B) Identification of lipids was confirmed by elution of the zones of interest with methanol from the HPTLC layer through a TLC-MS interface and a filter frit directly to a quadrupole-orbitrap MS (atmospheric pressure chemical ionization, full HR-MS scan in m/z range 100–1000). (C) For quantitative analysis, visualization at UV 366 nm after derivatization by immersion into primuline reagent (primuline 0.5 g/L in acetone – water 4:1); fluorescence was measured at UV 366 nm (mercury lamp, optical filter for wavelengths above 400 nm, scanning slit 6.0 mm × 0.2 mm, speed 20 mm/s). (A) and (B) allowed the separation and detection of cholesterol, cholesteryl oleate, methyl oleate, free fatty acids (FFA, expressed as oleic acid equivalents) and triacylglycerols (TAG, as triolein equivalents) in liver extracts. (C) showed that TAG was decreased and FFA increased in (3) and (4), compared to (1) and (2). Cholesterol and cholesteryl oleate had no significant changes between groups.

J. Pharm. Biomed. Anal. 189, 113488 (2020). Various extracts from red alga Plocamium dilatatum (Plocamiaceae), green alga Codium fragile tasmanicum (Codiaceae) and brown algae Carpoglossum confluens (1), Cystophora platylobium (2) and C. retorta (3) (Sargassaceae), Ecklonia radiata (Lessoniaceae), Hormosira banksia (Hormosiraceae), Phyllospora comosa (4) (Seirococcaceae) were separated on HPTLC silica gel with n-hexane – ethyl acetate – acetic acid 70:27:3. Detection A) for antioxidant activity by spraying with methanolic DPPH solution, followed by waiting for 30 min at room temperature; B) for steroids and terpenes with anisaldehyde - sulfuric acid solution, followed by heating for 10 min at 110°C; C) for carbohydrates and polyols with thymol - sulfuric acid, followed by heating for 15-20 min at 120°C. Image-based evaluation in white light and UV 366 nm. The most active bands were also characterized by ATR-FTIR (= attenuated total reflectance – Fourier-transformed infrared) spectroscopy.

Anal. Bioanal. Chem. 413, 1321-1335 (2021). HPTLC of estrone (1), 17β-estradiol
(2), 17α-ethinylestradiol (3), 5α-dihydrotestosterone (4), and progesterone (5) in wastewater and surface water samples on silica gel with a mixture of dichloromethane, cyclohexane, and acetone in different proportions. Detection by spraying with 8 % sulfuric acid in ethanol, followed by heating at 105 ºC for 10 min. Qualitative identification under UV light at 310 nm. Yeast multi endocrine-effect screen was performed by spraying the HPTLC plates with a mixed suspension of genetically modified Arxula adeninivorans yeast strains, which contain either the human estrogen, androgen, or progesterone receptor. The HPTLC plates were incubated at 30 ºC for 18 h and at 100 % humidity. After incubation, densitometric evaluation at: 445/K460 nm, 475/K500 nm and 542/K560 nm to determine the fluorescence of the cyan fluorescent protein (CFP, gestagen), green fluorescent protein (GFP, androgen), and DsRed2 protein (estrogen), respectively. The hRF values for (1) to (5) were 21, 22, 29, 34 and 39, respectively.

J. Planar Chromatogr. 34, 173-181 (2021). HPTLC of caffeic acid (1), chlorogenic acid (2), quercetin (3), oleanolic acid (4), lupeol (5), betulinic acid (6), β-Sitosterol (7), campesterol (8) and ergosterol (9) in samples of Echinops echinatus on silica gel with toluene - ethyl acetate - formic acid - methanol 30:30:8:3 for (1) and (2), toluene - ethyl acetate - formic acid 5:4:1 for (3), toluene - methanol 9:1 for (4), petroleum ether - ethyl acetate - toluene 7:2:1 for (5) and (6), toluene - ethyl acetate 9:1 for (7) and toluene - methanol - formic acid for (8) and (9). Quantitative determination by absorbance measurement at 254 nm for (1) to (3), 540 nm for (4) to (6) and 530 nm for (7) to (9). The hRF values for (1) to (9) were 69, 80, 60, 30, 68, 55, 26, 67 and 75, respectively. Linearity was between 2 and 12 µg/mL for (1) to (9). Intermediate precision was below 2 % (n=6). The LOD and LOQ were 38 and 119 ng/zone for (1), 18 and 57 ng/zone for (2), 364 and 1100 ng/zone for (3), 11 and 32 ng/zone for (4), 40 and 123 ng/zone for (5), 15 and 46 ng/zone for (6), 8 and 23 ng/zone for (7), 52 and 159 ng/zone for (8) and 527 and 1598 ng/zone for (9), respectively. Recovery was between 95.7 and 99.6 % for (1) to (9). 

Planta Med. 85(3), 195-202 (2019). The dichloromethane fraction of an ethanolic extract from Gloeophyllum odoratum sporocarp (Gloeophyllaceae, Basidiomycetes) was submitted to a multistep purification process (conventional, flash and supercritical fluid column chromatography). At each step, fractions were monitored on TLC silica gel with dichloromethane – methanol – water 40:4:1. Detection under white and UV light after derivatization with vanillin sulfuric acid 5 % in methanol and heating. Eight triterpenes were isolated for further identification: eburicodiol, gloeophyllins B and K, hydroxylanosterol, trametenolic acid B (all five from the lanostane type), gloeophyllins A and L (C‑nor-D-homoergosteroid type), and ergosterol peroxide (ergostane type).

J. Planar Chromatogr. 33, 271-279 (2020). Two-dimensional HPTLC of cholic, ursodeoxycholic, chenodeoxycholic, deoxycholic, and lithocholic bile acids on silica gel with 0.0001 M cetylpyridinium chloride at pH 9 with the addition of aliphatic alcohol modifiers 4 % 1-butanol (direction II) and 0.6 % 1-pentanol (direction II). Detection by drying the plate for 2-3 min in the oven at 120 ºC, followed by spraying with 8 % sulfuric acid in ethanol. Qualitative determination under UV light at 365 nm.

J. AOAC Int. 102, 708-713 (2019). TLC of snake bile in 20 species from three families (Elapidae, Colubridae, and Viperidae) on silica gel with xylene – isopropanol – methanol – glacial acetic acid – water 80:40:30:20:3. Detection by spraying with a 10% sulfuric acid ethanol solution, followed by heating at 105 ºC.  Qualitative identification under UV light at 366 nm. TLC coupled with quadrupole–time-of-flight–MS analysis of each zone was used for compound identification and evaluation.

J. Liq. Chromatogr. Relat. Technol. 42, 311-316 (2019). HPTLC of equol in cattle manure with methyl t-butyl ether - cyclohexane 1:1. The plate was scanned with a Time of Flight – Direct Analysis in Real Time – Mass Spectrometry (TOF-DART-MS) system. The hRF value of equol was 71. The LOD and LOQ for equol were 2.4 µg/zone and 4.5 µg/zone, respectively.