Food Chem. 383, 132597 (2022). HPTLC of protodioscin and escin in Camellia and Fenugreek on RP-18 with methanol - water - formic acid 65:35:1. Detection by spraying with 0.5 % p-anisaldehyde in a sulfuric methanol solution, followed by heating at 150 °C until visualization of zones.

Food Chem. 133992 (2023). HPTLC of kiwi peel extracts on silica gel with ethyl acetate - formic acid - acetic acid - water 100:11:11:26. Detection of phenolics and tanning agents by heating the plate at 100 °C for 2 min, followed by dipping into fast blue B (140 mg fast blue salt B in a mixture of 140 mL methanol, 10 mL water, and 50 mL dichloromethane). Detection of flavanols, phenols and further natural compounds by dipping into a NPA solution (1 g 2-aminoethyl diphenylborinate in 200 mL of ethyl acetate), followed by drying, detection under UV light at 366 nm, followed by dipping into the anisaldehyde reagent (0.5 mL anisaldehyde, 10 mL acetic acid, 85 mL methanol, and 10 mL sulphuric acid), followed by heating at 100 °C for 5 min. Antioxidants were detected by dipping into a DPPH solution (0.4 g 2,2-diphenyl-1-picrylhydrazyl in 200 mL of methanol), followed by incubation in dark for 30 min. 

Food Chem. 133263 (2022). HPTLC of 27 hand-filtered coffee brews of differently roasted coffee beans and 14 differently prepared and stored coffee brews on amino phase with a 3-step gradient: 1) methanol - ethyl acetate 13:7 (1), 2) ethyl acetate - toluene - formic acid - water 70:11:15:4, and stopped below the eluted alkaloids caffeine and theobromine; and 3) up to 13 mm with water - methanol 3:2. The hRF values for caffeine, theobromine, theophylline and 5-O-caffeoylquinic acid  were 95, 85, 18 and 21 in step (1), while for ferulic acid, coumaric acid, caffeic acid, nicotinic acid and gallic acid were 60, 54, 51, 35 and 10 during step (2), and for melanoids was 12 in step (3). The following effect-directed assays on the chromatogram were also performed: DPPH scavenging asay, Aliivibrio fischeri bioassay, Bacillus subtilis bioassay, acetylcholinesterase inhibition assay, α-glucosidase inhibition assay and planar yeast estrogen screen (pYES) bioassay. Further analysis by mass spectrometry using a electrospray interface. Coffee brews made by a fully automated coffee machine showed the highest antioxidative potential.

Food Chem. 131846 (2022). HPTLC of Trifolium medium L. (1) and Trifolium pratense (2) on silica gel with dichloromethane - methanol - ethyl acetate 5:10:11:20 for (1) and chloroform - ethyl acetate 3:2 for (2). The AChE inhibitory activity of individual compounds was examined by spraying with 1) acetyl cholinesterase, followed by incubation at 37 °C for 20 min, 2) 2 mM acetylthiocholine solution and 3) 2 mM 5,5´-dithiobis-(2-nitrobenzoic acid) solution, and visualized after 20 min.

Food Chem. 134184 (2023). HPTLC of 45 berry cultivars belonging to the nine species strawberry, raspberry, blackberry, black currant, blueberry, gooseberry, cape gooseberry, chokeberry, and goji berry on silica gel with toluene - ethyl acetate - formic acid - water 15:30:5:3. Detection by dipping into a 0.5 % solution of 2-aminoethyl diphenylborinate in ethyl acetate, followed by drying and dipping into a 5 % solution of PEG 400 in dichloromethane. Qualitative analysis under UV light at 366 nm. 

Food Chem. 133108 (2022). HPTLC of 135 baobab samples (Adansonia digitata) from different agroecological regions on silica gel with toluene - ethyl acetate - methanol - formic acid - water 60:50:25:3:5. Detection by dipping into aniline diphenylamine o-phosphoric acid reagent, p-amino benzoic acid reagent, or p-anisaldehyde sulfuric acid reagent, followed by heating at 120 °C for 5 min. Qualitative analysis under UV light at 254 nm. fluorescence detection at 366 nm and white light illumination. 

Food Chem. 133610 (2022). HPTLC of hormonal active compounds in 68 different botanicals on silica gel with ethyl acetate - toluene - formic acid - water 16:4:3:2. The plate was neutralized by spraying with citrate phosphate buffer (6 g/L citric acid monohydrate and 10 g/L disodium hydrogen phosphate in double-distilled water, adjusted to pH 12 by solid sodium hydroxide). To overcome diffusion caused by long bioassay incubation, zone fixation was achieved by coating with polyisobutyl methacrylate (0.25 % Degalan in n-hexane), followed by drying. The prepared yeast cell culture was piezoelectrically sprayed onto the plates, followed by incubation at 30 °C for 4 h. The substrate solution (2 mg 4-methyl umbelliferyl-β-D-galactopyranoside in 100 μL dimethyl sulfoxide and 3 mL citrate buffer) was piezoelectrically sprayed, followed by incubation at 37 °C for 1 h, dried, and documented by fluorescence light detection at 366 nm. The resulting NP-HPTLC–UV/Vis/FLD–pYAVAS–FLD bioassay allowed the detection of androgens, antiandrogens, false-positive antiandrogens, and synergists in complex mixtures.

Food Chem. 132941 (2022). HPTLC of monosaccharides glucose, galactose and rhamnose in Abroma augusta mucilage on silica gel with acetone - butanol - water 5:4:1. Detection by spraying with orcinol-sulfuric acid solution, followed by heating at 90 °C for 5 min.