CBS 105, 2-4 (2010). TLC and HPTLC of reaction samples from small molecule lead development, on silica gel with mixtures of methanol and dichloromethane/ethyl acetate or ethyl acetate and heptane/cyclohexane (ratios depending on the compound mixtures). Detection with primuline or berberine reagent. Direct elution into the MS with the TLC-MS interface. Substances not detected by DAD can successfully be measured by ELSD detection coupled to TLC.

J. AOAC Int. 96, 1209-1213 (2013). TLC of thujone (1) and 1,8-cineole (2) in the leaves of Artemisia adamsii essential oil on silica gel with toluene - ethyl acetate 93:7. Detection by dipping into vanillin - sulfuric acid reagent, followed by heating at 90 ºC for 3 min. The hRf values for (1) and (2) were 56 and 45. Bioautography by dipping into S. aureus suspension for 10 s. After drying for 2 min followed by incubation at 37 ºC for 17 h the plates were dipped in an aqueous solution of MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide 50 mg/80 mL) for 10 s and incubated at 37°C for 2 h. Inhibition zones appeared as pale yellowish zones against blue background.

Trends Anal. Chem. 78, 109-119 (2016). Review on the application of desorption electrospray ionization mass spectrometry (DESI-MS) for the analysis of biological samples. The review described different substrates in DESI-MS of plant, animal and human samples, including polytetrafluoroethylene/TLC surfaces. A comprehensive list of surfaces and solvents for the analysis of molecules such as salvinorin, divinatorin, metabolites from strawberries, potatoes, among others were described.

Planta Medica 83(03/04), 351-357 (2017). Acid hydrolysis of five new dammarane-type saponosides extracted from Panax japonicus var. major rhizomes for 5 h in methanol – HCl 1:1 in sealed capillary at 80°C, then TLC on silica gel with n-butanol – acetic acid – water 5:1:4 (upper phase) and with chloroform – methanol – water 16:8:1. After derivatization with aniline phthalic acid reagent, sugar moieties were identified as glucose units by comparison to standards. Note that in the title, by ignorance of the Latin grammar, the authors wrote “Panacis majoris” instead of the nominative “Panax major”. In the names of the compounds, the –ane or –ene ending was often also omitted.

J. Chromatogr. A 1506, 109-119 (2017). HPTLC of seven important steviol glycosides on silica gel, which may degrade in food products under certain processing and storage conditions, and additionally as a sum parameter their reported breakdown products steviol and isosteviol. Detection with 2-naphthol and primuline reagent. Baseline separation of steviol and isosteviol was achieved after a plate cut and subsequent short development (two-step method). The HPTLC method was robust with regard to varying sample matrix loads, provided a high sample throughput (23 separations in parallel on one plate), and was fast (total analysis time of 1 h: 30 min application, 15 min separation and 15 min derivatization/densitometry, leading to 2.6 min per sample). The solvent consumption was low (0.4 mL per analysis) and accuracy of the densitometric quantification was good. Confirmation of the results with HPTLC-ESI-MS of only the zones of interest instead of matrix or background so that there was less need for MS cleaning. Hyphenation to Aliivibrio fischeri bioassay to obtain information on bioactive compounds in Stevia leaf extracts.

Anal. Chem. 109-111 (1984). TLC of coccidiostats (lasalocid, septamycin and monensin) on silica with ethyl acetate - dichloromethane 7:3. Detection by UV transferring the spots by a specially-designed probe. Identification by fast atom bombardment mass spectrometry without elution.

Chem. Pharm. Bull. 34, 174-181 (1986). Description of a method for determination of the antioxidative activities of chemicals. Application of 1 Ál mixture of linolenic acid and test sample in ethanol to HPTLC plate, and peroxidation at 80 °C for 20 min. Detection of the lipid peroxides produced by spraying with alpha-methylindole reagent. Measurement by densitometry at 557 nm. Expression of the antioxidative activity of the test sample as the amount required to inhibit the peroxidation of linolenic acid by 50 %.

Anal. Chim. Acta 194, 199-209 (1987). TLC on silica with methanol - NH3 200:3. Detection by UV 254 nm. Record of the secondary-ion mass spectra after extraction from the layer.