Anal. Bioanal. Chem. 414, 4481-4495 (2022). HPTLC of selected caffeine-containing standards and beverages (Red Bull, Coca-Cola, coffee, and black tea) on different stationary phases (silica gel, RP- and cyano-) with propan-2-ol - n-heptane - water 7:3:1. Direct surface analysis of the TLC plates with a flowing atmospheric pressure afterglow (FAPA) ambient desorption/ionization source (TLC-FAPA-MS). CN-HPTLC plates were the most efficient stationary phase, resulting in a significantly more intense caffeine signal.

Phytochem. Anal. 33, 564-576 (2022). HPTLC of flavonoids (1), anthocyanin (2) and antioxidant structures in sweet cherry (Prunus avium) on silica gel with ethyl acetate - dichloromethane - formic acid - acetic acid - water 100:25:10:10:11 for (1) and ethyl acetate - formic acid - acetic acid - water 100:11:11:26 for (2). Detection by spraying with natural product reagent/polyethylene glycol 400 (NP/PEG) solution or 0.1 % methanolic DPPH solution. Qualitative analysis under UV light at 366 nm. 

J. Food Compos. Anal. 114, 104763 (2022). HPTLC of ergosterol in wheat, on silica gel with ethyl acetate - petroleum ether 3:2. Quantitative determination by absorbance measurement at 282 nm. The hRF value for ergosterol was 45. Linearity was between 40 and 600 ng/zone. Inter-day and intra-day precisions were below 4 % (n=6). The LOD and LOQ were 11 and 36 ng/zone. Recovery was between 103.7 and 107.7 %. 

Food Chem. 145, 109482 (2023). Review of analytical techniques and applications to assess authenticity of honey and detect adulterants, including TLC and HPTLC. In addition, HPTLC fingerprinting of lipophilic fractions of honey of various botanical sources. 

Chinese Medicine 10, 13 (2015). Samples were root and rhizome extracts of Panax notoginseng (Araliaceae), either raw or in the form of commercial granules. Standards were ginsenosides Rg1, Rb1, Rd, Re and Rg2, notoginsenoside NR1. TLC on silica gel with chloroform – ethyl acetate – methanol – water 15:40:22:9, followed by 10 min air drying. Derivatization for ginsenosides by immersion into sulfuric acid (10 % in ice cold methanol), followed by 10 min air drying and 5 min heating at 100 °C. Quantification by densitometric fluorescence measurement (deuterium and tungstene lamp, 366 nm). For each standard the linear range was 0.05-1 mg/mL (LOQ comprised between 38 and 431 µg/µL). As NR1 and Re (ratio ca. 2:1) had almost the same hRF, they were quantified together as one substance. Multivariate analysis through hierarchical (HCA) and principal component analyses (PCA) was used to order the samples into two clusters, according to the analyte concentrations, the raw plant extracts being richer than most of the commercial products. This TLC method was compared to quantification through UPLC-PDA (Ultra-performance liquid chromatography with photo diode array), which was more sensitive (LOQ between 10 and 49 µg/µL) but did not allow the separation between Rg1 and Re (ratio ca. 6:1).

Food Chem. 408, 135253 (2023). HPTLC of genotoxic compound zones in 33 oils on silica gel with chloroform - ethanol 5:1, up to 20 mm, then with n-hexane - diethyl ether 2:1, up to 40 mm, and finally with n-hexane - toluene 1:2 up to 60 mm. Detection in white light, UV 254 nm and 366 nm. Genotoxicity bioassay by spraying with Salmonella suspension with or without the S9 mixture (fraction from phenobarbital/β-naphthoflavone-induced lyophilized rat liver strain), followed by incubation at 37 °C for 3 h. The plate was dried and FDG (fluorescein di(β-D-galactopyranoside)) was sprayed, followed by incubation at 37 °C for 15 min. Cytotoxicity bioassay by spraying with MTT solution (0.2 % in phosphate buffer) after incubation with the Salmonella culture, followed by analysis under white light. Confirmative detection of aliphates was performed via a reagent sequence on the same plate by spraying with 1) Rhodamine 6B reagent, followed by detection in UV 366 nm and 2) phosphomolybdic acid reagent, followed by heating at 120 °C for 10 min, and documented at white light illumination.

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. 132937 (2022). Review of TLC assays, including cellular, enzymatic and chemical, and their application for effect-directed food-related analysis, in the last five years. TLC assays for the analysis of antioxidants and for the detection of enzyme inhibitors were described. Microorganism based TLC assays for the detection of antimicrobials, aflatoxins and estrogenic compounds were also presented. TLC methods for the detection of bisphenol and dioxin-like chemicals were described.