bispinosa Roxb. (Singhara). J. Planar Chromatogr. 26, 316-321 (2013). HPTLC of gallic acid (1), caffeic acid (2), quercetin (3) and kaempferol (4) in the green, red, and black fruits of Trapa natans var. bispinosa Roxb. (Singhara) on silica gel with toluene - ethyl acetate - formic acid 13:11:2. Quantification by absorbance measurement at 282 nm. The hRf values for compounds (1) to (4) were 23, 34, 38 and 46, respectively. Linearity was in the range of 1000-1500 ng/zone for (1) to (4). LOD and LOQ were 116 and 351 ng/zone for (1), 135 and 409 ng/zone for (29, 92 and 278 ng/zone for (3) and 87 and 263 ng/zone for (4), respectively. Average recoveries were 98.5 % for (1), 98.2 % for (2), 96.4 % for (3) and 97.3 % for (4). Intermediate/interday/intra-day precision was below 3 % (n=6).

Braz. J. Microbiol. 44, 401-406 (2013). HPTLC of trichothecene in multiplex PCR isolates of Fusarium culmorum on silica gel with chloroform - methanol - water 45:5:1. Detection by dipping into 10 % aluminium chloride in methanol-water mixture, followed by heating at 110 ºC for 20 min. Qualitative determination at UV 366 nm._x000D_

Food Chem. 187, 460-468 (2015). HPTLC-direct bioautography of bioactive compounds in the extracts of cold-pressed hemp (1), flax (2) and canola (3) seed oil on silica gel with toluene - ethyl acetate - formic acid - water 15:30:5:3 for (2) and toluene - ethyl acetate - acetic acid 80:25:4 for (1) and (3). HPTLC-DPPH scavenging activity was determined by dipping into a methanolic DPPH solution, followed by drying for 90 s in the dark and heating at 60 °C for 30 s. The hRF values of dominant radical scavenging zones were in the range of 75-85 for (1), 70-90 for (2) and 64 and 95-100 or (3). HPTLC-antimicrobial Aliivibrio fischeri assay allowed the determination of major antimicrobial zones at hRF 40-49 and 55-66 or (1), 23, 45 and 60 for (3) and 95 for (2). Additional effect-directed analyses employing acetylcholinesterase (AChE) assay, planar yeast estrogen (pYES) bioassay and Bacillus subtilis bioassay as well as subsequent HPTLC-ESI-MS allowed targeted characterization of bioactive compounds.

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.

CBS 116, 2-4 (2016). HPTLC of steroid alkaloid saponins from potato sprouts on silica gel with chloroform – methanol – water 60:40:9 with chamber saturation without filter paper over a migration distance of 70 mm. Detection by dipping half of the plate in anisaldehyde-sulfuric acid reagent, drying for 10 min and heating at 70 °C for 5 min. The other half of the plate was used for the blood-gelatin test: dipping in 0.5 % polyisobutylmethacrylate in n-hexane – chloroform 20:1 for 10 s, coating with 40 mL blood-gelatin (2 % gelatin in PBS buffer pH 7.4 with 3 % human blood preservation), storage for 12-48 h at 4 °C. Evaluation under UV 366 nm and white light. Semiquantitative evaluation of the hemolytic activity using the substance digitonin from potato sprouts. The hemolytic activity of α-chaconine was comparable to the effect of 16-20 µg digitonin.

J. Agric. Food Chem. 64, 8246-8253 (2016). HPTLC of ricinoleic acid in Secale cornutum on silica gel with cyclohexane – diisopropyl ether – formic acid 86:14:1. Detection by dipping into a solution of n-hexane – paraffin oil 2:1. Quantitative determination by fluorescence measurement at 280/>340 nm. The hRF value for ricinoleic acid was 33. Linearity was between 0.1 and 1.8 ng/zone. The intermediate precisions were below 3 % (n=5). The LOD and LOQ were 0.06 and 0.2 ng/zone, respectively.

Food Chem. 239, 831-839 (2018). HPTLC of saffron on silica gel with 1-butanol – acetic acid – water 4:1:1. Qualitative identification at UV 254 nm. The hRf values of the nine detected zones (crocins and picrocrocin derivatives) were 19, 29, 43, 56, 63, 67, 80, 85, and 96. Captured images were imported to the MATLAB program for pattern recognition and discrimination between different saffron samples on the basis of their soil electro-conductivity values as indicator of soil salinity. The data pre-processing included elimination of chromatographic artifacts such as baseline drifts and spot misalignment.

J. Liq. Chromatogr. Relat. Technol. 41, 282-300 (2018). Review of TLC methods used for the analysis of 20 of the most used spices (chilies, pepper, ginger and mustard from hot spices; coriander, paprika and turmeric from mild spices and ajwain, allspice, cardamom, cassia, cinnamon, clove, cumin, dill, fennel, fenugreek, mace, nutmeg and saffron from aromatic spices). The comprehensive review included TLC methods for determination of antioxidant activity, antibacterial/antimicrobial activity, enzyme inhibitory activity, antifungal acivity and estrogen-like activators.