Pharmacogn. Mag. 17, 233-239 (2021). HPTLC of esculin in the leaves of Launaea pinnatifida on silica gel with chloroform - methanol - formic acid 13:6:1. Quantitative determination by absorbance measurement at 343 nm. The hRF value of esculin was 70. Linearity was between 8 and 250 µg/mL. The LOD and LOQ were 8 and 25 µg/zone. Average recovery rate was 99.8 %.

Bioorg. Chem. 88, 102947 (2019). HPTLC of pentylcurcumene in the aerial part of Geophila repens on silica gel with benzene - methanol 3:1. Quantitative determination by absorbance measurement at 254 nm. The hRF value of pentylcurcumene was 50. Linearity was between 100 and 500 ng/zone. The intermediate precision was below 2 % (n=3). The LOD and LOQ were 16 and 49 ng/zone. Recovery was between 97.2 and 98.7 %.

Rapid Commun. Mass Spectrom. 34, 8631 (2020). A 3D-printed, fully automated, open-source add-on user interface was built for elution-head-based TLC/HPTLC-MS. The system allowed a very compact plate-positioning system combined with an image-based software solution providing a platform to control and synchronize all steps from positioning, elution, advanced cleaning to MS data acquisition.

Rapid Commun. Mass Spectrom. 34, 8875 (2020). HPTLC of glycolipids in sperm from different fish species on silica gel with chloroform - ethanol - water - triethylamine 30:35:7:35. Detection by dipping into primuline (dissolved in acetone - water 4:1). Further analysis by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) and electrospray ionization ion trap (ESI-IT)MS.

Rapid Commun. Mass Spectrom. 34, 8755 (2020). HPTLC of a synthetic formulated gasoline (diluting polypropylene glycol and polyisobutylene succinimide polyamine surfactant at a mass ratio of 1 % in gasoline) on silica gel with methanol - toluene 2:3. Detection under UV light. Samples were scratched for analysis by atmospheric solids analysis probe mass spectrometry (ASAP-MS).

Rapid Commun. Mass Spectrom. 35, 9013 (2021). Review of the application of direct analysis in real time (DART) combined with mass spectrometry (MS) detection in food science and industry published in the period from 2005 to this date. The applications described the use of HPTLC in preparation methods as well as the combination of HPTLC fingerprints and DART-MS with multivariate data analysis for the differentiation of natural propolis products.

J. Sep. Sci. 44, 3146-3157 (2021). HPTLC of  gallic acid (1), cinnamic acid (2), piperine (3), eugenol (4), and glycyrrhizin (5) in Divya-Swasari-Vati on silica gel with ethyl acetate - toluene - formic acid 10:9:1 for (1) to (4) and ethyl acetate - formic acid - acetic acid - water 100:10:10:23 for (5). Quantitative determination by absorbance measurement at 280 nm for (1), (2) and (4), 343 nm for (3) and 254 nm for (5). The hRF values for (1) to (5) were 31, 64, 53, 70 and 29, respectively. Linearity was between 400 and 800 µg/mL for (1), 5 and 25 µg/mL for (2), 600 and 1400 µg/mL for (3), 400 and 1200 µg/mL for (4) and 100 and 800 µg/mL for (5). Intermediate precision was below 2 % (n=18). The LOD and LOQ were 180 and 560 ng/g for (1), 3 and 10 ng/g for (2), 8 and 26 µg/g for (3), 3 and 11 µg/g for (4) and 300 and 920 ng/g for (5), respectively. Mean recovery was 96.0 % for (1), 92.3 % for (2), 94.2 % for (3), 96.2 % for (4) and 94.6 % for (5). 

J. Ethnopharmacol. 276, 114144 (2021). Review of analytical methods for the analysis of the main secondary metabolites detected and isolated from Ammi majus. The paper described TLC and HPTLC methods for the determination of coumarins in fruits.