J. Planar Chromatogr. 30, 199-204 (2017). HPTLC of sophoridine (1), matrine (2), and sophocarpine (3) in S. alopecuroides on silica gel with toluene – acetone – methanol – ammonia – water 80:30:2:5:80. Detection by spraying with bismuth potassium iodide reagent (1:1 mixture of 0.85 g of bismuth nitrate with 10 mL of glacial acetic acid and 40 mL of water, heated for dissolution, and 8 g of potassium iodide in 30 mL of water). Quantitative determination by absorbance measurement at 500 nm. The hRF values for (1) to (3) were 22, 56 and 65, respectively. Linearity ranged from 415-2491 ng/zone for (1), 424-2547 ng/zone for (2) and 410-2460 ng/zone for (3). The intermediate precision was <5 % (n=3). Recovery rate ranged from 97.8 to 98.9 % for (1), 98.3 to 100.9 % for (2) and 99.1 to 101.2 % for (3).

CBS 119 (2017) 14-15. HPTLC of Cannabis sativa and standards cannabidiol (CBD), tetrahydrocannabinol (THC), and cannabinol (CBN) on silica gel with n-heptane – diethyl ether – formic acid 75:25:0.3 with chamber saturation for 20 min to a migration distance of 70 mm. Detection by spraying with Fast Blue salt B reagent (250 mg o-dianisidine bis(diazotized) zinc double salt in 10 mL water, 25 mL methanol and 15 mL dichloromethane), evaluation under white light. Quantitative determination by absorbance measurement at 210 nm prior to derivatization (for cannabinoid acids 285 nm). For the screening of THC-free samples the limit test can be used. The EU limit of 0.2 % is easily detected with or without detection. The %RSD of the assay prior to derivatization is 1.5 % and after derivatization 2.1 %. The LOD is 10 ng/zone.

J. AOAC Int. 99, 1204-1212 (2016). HPTLC of St. John’s wort labeled as Hypericum perforatum on silica gel with ethyl acetate – dichloromethane – formic acid – acetic acid – water 100:25:10:10:11 (USP 38-NF33), ethyl acetate – formic acid – water 30:2:3 (European Pharmacopoeia) and ethyl acetate – acetic acid – formic acid – water 100:11:11:26 (USP 37-NF32). For the investigation of synthetic dyes, samples were analyzed on RP-18 with methanol – 5 % aqueous sodium sulfate 3:4. Detection by dipping into natural products reagent (1 g diphenylborinic acid 2-aminoethylester in 200 mL ethyl acetate), then in polyethylene glycol reagent (10 g PEG 400 (macrogol) in 200 mL dichloromethane). Qualitative identification under UV 254 and 366 nm. A decision tree was developed to analyze adulterated samples labeled as Hypericum perforatum. If for example under UV 366 nm after derivatization a yellow fluorescent zone is seen at hRF 46, samples are probably mixed with another undesired species. In addition, if a bluish zone is seen at application position of samples identified with the test USP 38-NF32 and examined under white light prior derivatization, the sample is probably mixed with dyes.

in experimental animals. J. Ethnopharmacol. 224, 15-26 (2018). HPTLC of quercetin in the flowers of C. trenatea on silica gel with chloroform – methanol – formic acid 15:3:2. Quantitative determination by absorbance measurement at 254 nm. The hRf value of quercetin was 52.

J. Planar Chromatogr. 31, 163-168 (2018). HPTLC bioautography of the essential oil in the bark of Ocotea quixos on silica gel with toluene – ethyl acetate – petroleum ether 97:7:20. After separation, the Mueller‒Hinton culture medium was deposited on the Petri dish which contained the chromatographic plate. The medium contained the selected microorganisms: 500 μL Bacillus subtilis ATCC 6633 ATCC and 500 μL P. aeruginosa ATCC 9027. The plate was incubated at 37 °C for 48 h. The molecule with activity proved to be cinnamyl acetate at an hRF value of 53.

germplasms from Western Himalayas. Pharmacogn. Mag. 14, 141-146 (2018). HPTLC of precocene I (1) and precocene II (2) in the germoplasms of Ageratum conyzoides on silica gel with toluene – ethyl acetate 49:1. Quantitative determination by absorbance measurement at 300 nm. The hRF values (1) and (2) were 60 and 23, respectively. Linearity was between 100 and 500 ng/zone for both (1) and (2). LOD and LOQ were 5 and 16 μg/mL for both (1) and (2). The intermediate precision was <5 % (n=3). Average recovery was 99.7 % for (1) and 102.9 % for (2).

J. Planar Chromatogr. 31, 421-428 (2018). HPTLC of solamargine in Solanum species on silica gel with dichloromethane ‒ methanol ‒ 2.5% aqueous ammonia 75:25:2. Detection by dipping into anisaldehyde sulfuric acid reagent, followed by heating at 110 °C. Quantitative determination by absorbance measurement at 540 nm. The hRF value for solamargine was 15. Linearity was between 25 and 300 ng/zone. LOD and LOQ were 1 and 4 ng/zone. The intermediate precision was <2 % (n=3). Average recovery was 101.2 %.

(Dryopteridaceae, pteridophyte). Helv. Chim. Acta 68, 1251-1274 (1985). TLC of various complex phloroglucinols on silica impregnated with citric acid - phosphate buffer using methanol - isopropyl ether - cyclohexane 10:35:55, chloroform - hexane - ethanol 45:45:10, chloroform - hexane - ethanol - acetic acid 45:35:16:4 or ethyl acetate - cyclohexane - acetic acid 60:35:5. Detection by UV 254 and 366 nm and by spraying with a 0.1 % sol. of "fast blue salt B". Checking of doubtful spots was achieved by scraping, elution with ethyl acetate/ether and rechromatography in another system.