J Chromatogr A, 1624, 461239 (2020). Samples were chemical standards of acetylcholinesterase (AChE) inhibitors (azamethiphos, caffeine, donepezil, galanthamine, methiocarb-sulfoxide, paraoxon-ethyl) and of neurotoxic compounds, as well as drinking or contaminated water samples enriched through solid phase extraction. HPTLC on spherical silica gel (pre-washed twice by 20 min immersion in isopropanol, heated 20 min at 120 °C before and after pre-washing with acetonitrile). First separation (preparative TLC) with automated multiple development (16 steps). Effect-directed analysis for AChE inhibitors by immersion (speed 5 cm/s, time 1 s) into enzyme solution, incubation 5 min at 37 °C and immersion into substrate solution (indoxyl acetate 2 % in methanol); visualization under UV 366 nm. Active zones from untreated layers were eluted through the oval head of a TLC-MS interface to a second plate for a second separation with a panel of other mobile phases. Bands of interest were eluted from the second layer with water through the oval elution head of the TLC-MS interface pump, into a RP18 liquid chromatography guard column, followed by a quadrupole time-of-flight mass spectrometer. Full scan mass spectra (m/z 100–1200) were recorded in negative and positive modes using electrospray ionization (and collision-induced dissociation for MS2). Among the water contaminants, lumichrome (riboflavin photolysis product), paraxanthine and linear alkylbenzene sulfonates were identified as AChE inhibitors.

Molecules, 26 (24), 7683 (2021). Samples were ultrasound-assisted extracts of fruit puree and juice (pre-treated with sulfur dioxide or ascorbic acid) of Ananas comosus (Bromeliaceae) and Mangifera indica (Anacardiaceae). HPTLC on silica gel with toluene – ethyl acetate – methanol – formic acid 120:90:35:3. Detection under white light, UV 254 nm and 366 nm, before and after  derivatization by immersion (2 s, 3 cm/s) into anisaldehyde sulfuric acid reagent and  diphenylamine aniline reagent, followed by heating at 110 °C for 5 min. Effect-directed analysis using automated immersion: A) for free radical (DPPH•) scavengers; B) for enzymatic inhibition (acetyl-cholinesterase, tyrosinase); C) for activity against Gram-negative (Aliivibrio fischeri bioluminescence assay) or Gram-positive bacteria (Bacillus subtilis bioassay). Active compounds were far more present in puree than in juice extracts, and differences were also seen between cultivars. Ascorbic acid (hRF 37), used as additive for the mango puree, was active as antioxidant and as transiently disruptive for A. fischeri metabolism and bioluminescence.

Indian Police Journal LVI 4, 55-64 (2009). A TLC method has been developed for checking counterfeit Indian currency using TLC scanning and photo imaging technique. For comparison, scanning of the security thread of both genuine and counterfeit 500 rupees bills was performed by multi-wavelength absorbance measurement of the entire area covering the intaglio ink portion. Fluorescence evaluation at 366 nm of both genuine and counterfeit rupee bills showed the security features of genuine bills very well. A regular, good absorbance pattern was observed on the surface of genuine bills whereas in case of counterfeit currency there was an irregular absorbance pattern. Under white light no major difference was found between genuine and counterfeit bills.

Chinese Anal. Chem. (Fenxi Huaxue) 26, 120 (1998). TLC on silica with benzene - ethyl acetate - acetic acid 240:50:3. Detection under UV 254 nm. Quantification of methyl-, ethyl-, propyl- and butyl-hydroxybenzoates by densitometry at 260 nm. Calculation of the yield for each. Detection limits 100, 100, 200, 300 ng/spot, respectively.

J. Liq. Chromatogr. Relat. Technol. 37, 2249-2257 (2014). HPTLC of benzyltrimethylammonium chloride (1), dodecyltrimethylammonium chloride (2), tetrabutylammonium bromide (3), and methyltrioctylammonium bromide (4) on silica gel with methanol - 5 % aqueous EDTA 7:3. Detection by spraying with Dragendroff reagent. The hRF values for (1) to (4) were 32, 43, 62 and 75, respectively.

J. Chromatogr. 446, 17-22 (1988). TLC of non-ionic surfactants on alumina with carbon tetrachloride - acetonitrile in various proportions. Detection by spraying with modified Burger reagent and densitometry at 500 nm. Discussion of the relationship between the length of the ethylene oxide chain and the strength of the solvent system.

Chinese J. Chem. World (Huaxue shijie) 35 (2) 89-90 (1994). TLC on silica with butanol - acetic acid - water - EDTA solution (0.1 mol/L) 500:167:333:27. Detection by exposure to iodine vapor.

J. Planar Chromatogr. 28, 436-442 (2015). TLC of hydrocortisone acetate (1), fusidic acid (2), methyl paraben (3) and propyl paraben (4) on silica gel with methylene chloride – methanol – benzene 10:2:5. Quantitative determination by absorbance measurement at 240 nm. The hRF values for (1) to (4) were 13, 32, 49 and 59. The polynomial calibration range was between 1-15 μg/zone for (1) to (4). The intermediate precision was below 1.8 % (n=3). Recovery ranged 99.6-100.2 %.