J. Food. Biochem. 45, e13764 (2021). HPTLC of L-arabinose, D-fructose, D-fucose, D-galactose, D-glucose, D-mannose, D-rhamnose, D-xylose in the roots of Sechium edule on silica gel with chloroform - n-butanol - methanol - water - acetic acid 9:15:10:3:3. Detection by spraying with 5 % sulfuric acid in methanol containing 0.1 % orcinol, followed by heating at 80 °C for 5-10 min.

Plant Med 88(2), 163-178 (2022). TLC was used to verify the purity of acetoxychavicol acetate (a phenylpropanoid) isolated through column chromatography from a hexane extract of Alpinia galanga rhizomes (Zingiberaceae). TLC on silica gel with n-hexane – ethyl acetate 17:3, evaluation under UV 254 nm.

J. Food. Biochem. 46, e13855 (2022). HPTLC of Amomum subulatum dry fruits on silica gel with toluene - ethyl acetate - methanol - formic acid 14:6:2:1. Qualitative identification under UV light at 254 and 366 nm. 

Front. Pharmacol. 12, 678611 (2021). HPTLC of withanolide S in Withania somnifera and myristicin in Myristica fragrans on silica gel with toluene - ethyl acetate - acetic acid 5:4:1. Detection of myristicin under UV 254 nm. Detection of withanolide S by spraying with 5 % anisaldehyde sulfuric acid, followed by visualization under UV 540 nm. Screening of anticholinesterase active metabolites by spraying with DTNB/ATCI reagent (1 mmol/L 5,5-dithiobis-(2- nitrobenzoic acid) and 1 mmol/L acetyl thiocholine iodide). 

Anal. Bioanal. Chem. 414, 5991-6001 (2022). 2D-HPTLC fingerprint of Alpinia officinarum on silica gel in 384-well microplate array format (4.5 × 4.5 mm) matrix with trichloromethane - methanol - petroleum ether 97:3:25 in the first dimension and ethyl acetate - petroleum ether - acetic acid 15:35:1 in the second dimension. The paired chromatographic-based microassay array with the consistent chromatographic distribution was prepared by transferring a portion of the sample from the stock chromatographic-based microassay arrays to the corresponding array units of another 384-well microplate. A G‑quadruplex ligand bioassay was used to evaluate the ligand activity of the components in each array unit of the chromatographic-based microassay array. Further analysis by mass spectrometry. 

Chinese Medicine 15, 76 (2020). This review compared the 2020 editions of Chinese (ChP) and European Pharmacopoeas (EuP) in different aspects of quality control of traditional Chinese medicinal plants (73 of which drugs were common to both, but with differences in species or organs for 17 of them). Discussed points included history, identification, plant origin and processing, sample preparation, marker selection, tests and assays, as well as advanced analytical techniques for quality control and for the establishment of comprehensive quality standard. TLC was discussed in relation to its following aspects: purposes, markers/references, techniques and result description.
(A) The main uses of TLC and HPTLC were (1) chemical-based identification of the plant in a more accurate and precise method than by macroscopic and microscopic observation only, and in a more direct and easily interpretation than HPLC, and allowing the simultaneous analysis of multiple samples in parallel; (2) control of possible adulterants; (3) quantification of active compounds. Both uses (1) and (2) were combined in some EuP monographs: as example were given the roots of Angelica dahurica, A. pubescens, A. sinensis, using TLC for identification of the species and of adulterants from other species (Angelica, Levisticum and Ligusticum).
(B) In ChP, identification through TLC was in most cases achieved by fingerprint comparison to an official reference extract or herb (herbal reference substance). At the opposite, EuP often indicated analytical markers, irrespective of any pharmacological activity, but chosen only for analytical purposes in TCM identification and quantification. Examples were: aescin and arbutin as analytical markers for TLC identification of Anemarrhena asphodeloides rhizome and Panax notoginseng root.
For the TLC system suitability assessment tests, ChP used the same intensity markers or active markers that were chosen for the identification or assay; whereas EuP often used other specific references, e.g. isoeugenol and methyleugenol in the case of Ophiopogon japonicus roots.
(C) For the techniques, conventional separations and chemical derivatizations were used. Hyphenations of TLC to other analytical methods (e.g. MS) were absent. Only one monograph applied an effect-directed analysis directly on TLC chromatogram (free DPPH• radical scavenging assay for TLC identification of Rehmannia glutinosa root, in ChP).
Sometimes, the TLC methods were different between both reference books for the same species. Example was given for Belamcanda chinensis (=Iris domestica) rhizome: in EuP, development on silica gel with cyclohexane – ethyl acetate – acetic acid 20:80:1, detection under UV 254 nm, comparison to standards coumarin and irisflorentin; whereas in ChP, development on polyamide layer with chloroform – butanone – methanol (3:1:1), detection under UV 365nm after derivatization with aluminium chloride, comparison to a reference rhizome powder.
 (D) Finally, the results in ChP were described as a text stating the similarity of sample profile with the profile of the chosen reference, whereas the results in EuP were described with a schematic box indicating the positions of bands of interest.

J. Ethnopharmacol. 295, 115327 (2022). Review of modern applications for the analysis of Rauvolfia species, including traditional uses, phytochemistry, quality control, pharmacological properties, as well as clinical evidence that may be useful in the drug discovery process. The paper described qualitative and quantitative methods, including HPTLC methods for the analysis of targeted and non-targeted compounds in different extracts of plant parts of Rauvolfia species.

J. Ethnopharmacol. 289, 115035 (2022). HPTLC of stigmasterol and some polyphenolic compounds in the rhizome of Cyperus tegetum on silica gel with chloroform - ethyl acetate - formic acid 5:4:1 and toluene - methanol 9:1. Detection by spraying with p-anisaldehyde reagent in a cold solution of methanol - glacial acetic acid - phuric acid 17:2:1, followed by heating at 100 - 105 °C for 5-10 min.