J. Liq. Chromatogr. Relat. Technol. 34, 2664-2673 (2011). HPTLC of curcumin (1) and gallic acid (2) in pharmaceutical formulations containing Curcuma longa Linn and Emblica officinalis extracts, on silica gel with chloroform - ethyl acetate 5:4 + 1 drop formic acid. Quantitative determination by absorbance measurement at 254 nm. The hRf values of (1) and (2) were 55 and 26, respectively. Linearity was between 30-700 ng/zone for (1) and 100-700 ng/zone for (2). LOD and LOQ were 100 and 300 ng/zone for (1), and 33 and 100 ng/zone for (2), respectively. The intermediate/inter-day/intra-day precision (n = 6) was 0.3 % for (1), and 0.1 % for (2). Recoveries (by standard addition) were 98.2-104.0 % for (1) and 97.8-101.5 % for (2).

Jiangxi J. of Trad. Chinese Med. 43 (351), 67-68 (2012). Flavonoids are the main active component in dried leaves of Microcos paniculata Linn. This traditional Chinese herbal crude drug lowers the blood pressure and blood fat, prevents from cardiovascular diseases and anti-aging effects. In order to develop a quality control method for Microcos paniculata Linn. the reference substances vitexin, isovitexin and narcissoside were analyzed with 16 samples of Microcos paniculata Linn. available from different places of origin. TLC of the extracts of the drug samples and the reference substances on silica gel with ethyl acetate – methanol – water 100:17:13, detection by spraying with 10 %sulfuric acid in ethanol, followed by heating at 105 °C for 5 min and viewing in UV 366 nm. Densitometric analysis at 366 nm with a mercury lamp in reflection mode, a scanning speed of 20 mm/s and a resolution of 25 µm/step. Identification of the flavonoids in the samples to be tested by fingerprint comparison of both the fluorescence chromatograms and densitograms.

J. Liq. Chromatogr. Relat. Technol. 36, 1528-1539 (2013). HPTLC of mebeverine hydrochloride (1), metronidazole benzoate (2), diloxanide furoate (3) and metronidazole (4) in pharmaceutical suspensions on silica gel with hexane - acetone - triethylamine 35:15:3. Quantitative determination by absorbance measurement at 254 nm. The hRf values of compounds (1) to (4) were 10, 34, 49 and 64, respectively. Linearity was 0.4-2.4 µg/zone for (1), 0.3-2.0 µg/zone for (2) and 0.4-2.4 µg/zone for both (3) and (4). Intermediate precision was below 1.2 %. Recovery (by standard addition) was 99.9-100.1 % for compounds (1) to (4). Comparable results were obtained when compared with reported RP-HPLC methods.

J. Planar Chromatogr. 26, 132-136 (2013). TLC of rosmarinic (1) and caffeic acids (2) in extracts of Salvia species on silica gel with toluene - ethyl acetate - formic acid 5:4:1. Quantitative determination by absorbance measurement at 325 nm. The hRf values for (1) and (2) were 40 and 60, respectively.

J. Planar Chromatogr. 27, 11-18 (2014). HPTLC of fructose (1), glucuronic acid (1), galacturonic acid (3), rhamnose (4), xylose (5), arabinose (6), and galactose (7) in the seeds of Ocimum basilicum on silica gel with isopropyl acetate - ethyl acetate - ethanol - water 50:40:10:1. Detection by dipping into aniline diphenylamine o-phosphoric acid reagent (20 % of o-phosphoric acid [85%] added to 1:1 mixture of 2 % solutions of diphenylamine and aniline in acetone), followed by heating at 110 ºC for 5 min. Quantitative determination by absorbance measurement at 630 nm except for (4) which was determined at 370 nm. The hRF values for (1) to (7) were 80, 58, 51, 40, 25, 18 and 9, respectively.

J. Planar Chromatogr. 27, 294-298 (2014). HPTLC of amiloride hydrochloride (1) and torsemide (2) in dosage forms on silica gel with chloroform - methanol - ammonia 15:7:2. Quantitative determination by absorbance measurement at 286 nm. The hRF values for (1) and (2) were 46 and 24, respectively. Linearity was in the range of 50-300 ng/zone for (1) and 100-600 ng/zone for (2). The intermediate/inter-day/intra-day precision were below 4 % (n=3). The LOD and LOQ were 16 and 50 ng/zone for (1) and 33 and 100 ng/zone for (2), respectively. Recoveries for (1) and (2) were between 97.4 and 99.5 %.

extracts. J. Planar Chromatogr. 28, 178-183 (2015). TLC of (1) chlorogenic acid and (2) caffeine in coffee samples on silica gel with ethyl acetate - methanol - water 77:13:10 to a distance of 8 cm using a horizontal sandwich chamber. The plates were dried at room temperature for 1 h. Detection of polyphenols with NP-PEG reagent, of terpenoids with anisaldehyde-sulfuric acid reagent followed by heating at 110 °C for 5 min, of purine derivatives with iodine-hydrochloric acid reagent. Quantitative determination of (1) and (2) at UV 254 nm using VideoScan software. The hRF value of (1) was 14, and of (2) 51. The antibacterial activity of green and roasted coffee seeds and pomace was evaluated against Bacillus subtilis using TLC-direct bioautography. TLC-2,2-diphenyl-1-picrylhydrazyl (DPPH) test was used to determine the antioxidant properties. For bioautography with Bacillus subtilis, the plates were immersed for 8 s in the bacterial suspension, placed in a moistened plastic box, and incubated at 37 °C for 17 h. Detection after spraying with 0.2 % MTT aqueous solution. For the DPPH test, plates were sprayed with 0.2 % methanolic DPPH solution. Detection of antioxidant activities as yellow zones against a purple background.

CBS 116, 13-15 (2016). HPTLC of nicotine in e-liquids on silica gel with chamber saturation (with filter paper) for 20 min with toluene – acetone –diethylamine 10:10:1 to the migration distance of 70 mm. Detection under UV 254 nm. Quantitative determination by absorbance measurement at 260 nm. Elution of the zones with methanol (with 0.1 % formic acid) into a single quadrupole MS and detection in positive ionization mode. The hRf value of nicotine was 56 and separation from other ingredients (propylene glycol, glycerol, flavors) was good. Visual evaluation of the samples for presence of nicotine was confirmed with MS and UV spectra.