J. Planar Chromatogr. 23, 225-226 (2010). OPLC of oregano oil components (carvacrol, thymol, and linalool) on silica gel with dichloromethane. Detection under UV 254 nm, by spraying with vanillin-sulfuric acid reagent (0.1 g vanillin, 100 mL ethanol, and 2.2 mL 95-98 % sulfuric acid) and heating at 110 °C for 3 min, and in the BioArena system (the dried developed plates were dipped for 10 s into an aqueous cell suspension of the soil bacteria Bacillus subtilis and incubated for 2 h at 100 % rel. humidity and 30 °C). Visualizion of antimicrobial compounds was performed by immersing the plates for 5 s in an aqueous solution of MTT reagent (80 mg MTT and 100 mg Triton X-100 in 100 mL water). The layers were further incubated and and documented.

Microbiol. Res. 166, 255-267 (2011). TLC of lipopeptides (produced by Pseudomonas species in cultures of Pleurotus ostreatus; Pseudomonas reactans was used as a reference) on silica gel with chloroform – methanol – ammonia 80:25:4. Detection by spraying with 0.1 % bromothymol blue in ethanol, followed by heating.

J. Planar Chromatogr. 24, 57-59 (2011). HPTLC of piperine on silica gel with toluene - ethyl acetate - diethyl ether 6:3:1 in a saturated twin trough chamber. The hRf of piperine was 40. Quantitative determination by densitometry at 337 nm. Linearity was between 15 and 75 ng/zone. LOD and LOQ was 5 and 15 ng/zone, respectively. The recovery was 94.5 %. The instrumental precision, repeatability, intra-day and inter-day precision (%RSD, n = 6) was 0.6 %, 0.8 %, 0.9 and 0.8 %, respectively.

J. Planar Chromatogr. 25, 534-541 (2012). TLC of anthocyanins and anthocyanidins in berry fruits on cellulose layers with hydrochloric acid - glacial acetic acid - water 10:1:3. Quantitative determination by absorbance measurement at 520 nm. The hRf values obtained for pelargonidin and cyanidin were 78 and 58, respectively. The TLC method was complementary to an HPLC method and allowed for identification of the major anthocyanidins characteristic for each berry fruit.

Food Chemistry. 139, 866-871 (2013). HPTLC of catechin (1), proanthocyanidin (PAC) A2 (2) and PAC-B1 (3) in American cranberry (Vaccinium macrocarpon) extracts on silica gel with dichloromethane - ethyl acetate - formic acid 6:10:1. Detection by dipping into a hydrochloric solution of 1 % (w/v) vanillin, followed by heating at 110 °C for 2 min. Quantitative determination by absorbance measurement at 254 and 366 nm. The hRf values of (1), (2) and (3) were 63, 48 and 25, respectively. Linearity was in the range of 0.6-5 µg/band. Intermediate precision was below 2.1 %. Average recoveries (by standard addition) were 98.4 % for (1), 99.6 % for (2) and 98.5 % for (3).

Food Chem. 156, 94-99 (2014). TLC of epigallocatechin gallate (1), gallic acid (2) and caffeine (3) on silica gel with dichloromethane - acetone - formic acid 8:7:1. Detection by dipping into 5 % methanol - sulfuric acid reagent, followed by heating at 105 °C for 3 min. Quantitative determination of (1) as gallic acid equivalents by absorbance measurement at 270 nm (epigallocatechin gallate (EPCG) was calculated and expressed as gallic acid equivalents because the EPCG standard is very expensive). The hRF values for (1) to (3) were 54, 69 and 80. Linearity was in the range of 500-5000 ng/zone for (2) and 200-2400 ng/zone for (3). The intermediate/inter-day/intra-day precisions were below 2 % (n=3). The LODs and LOQs were 400 and 500 ng/zone for (2) and 180 and 200 ng/zone for (3), respectively. Recoveries were between 94.9 and 100.0 % for (2).

Plant Breeding 134, 129-134 (2015). HPTLC screening of flavonoids in more than 1800 taro hybrids (Colocasia esculenta (L.) Schott) on silica gel with ethyl acetate - methanol - acetic acid - formic acid - water 30:1:2:1:3. Detection by heating at 100 °C for 3 min, followed by dipping with natural product reagent. Qualitative determination by absorbance at 366 nm. Scoring of the absence and presence of a selection of 8 zones for each track followed by statistical retreatment permitted to sort samples per family. This method contributed to taro genetic improvement.

Tecnología Química (RTQ) 35, 181-192 (2015). TLC of inulin in Tuna on silica gel with butanol - isopropanol - water - acetic acid 7:5:4:2. Detection by spraying with a solution of aniline - diphenylamine - phosphoric acid - acetone 1:1:5:50, followed by heating at 85 °C for 10 min. The hRF value for inulin was 87.