J. AOAC Int. 98, 1226-1233 (2015). HPTLC of three phosphodiesterase type 5 inhibitors, sildenafil (1), vardenafil (2), and tadalafil (3), and eight of their analogs, hydroxyacetildenafil (4), homosildenafil (5), thiohomosildenafil (6), acetildenafil (7), acetaminotadalafil (8), propoxyphenyl (9), hydroxyhomosildenafil (10), hydroxyhomosildenafil (11) and hydroxythiohomosildenafil (12) in finished products on silica gel with TBME - methanol - ammonia 28% 20:2:1. Detection under 254 and 366 nm UV light and by absorbance measurement at 232 nm. LOD was 30 ng/zone for all substances. Confirmation by HPTLC-ESI-MS. The method was successfully_x000D_ applied to screening of 45 commercial lifestyle products. Of those, 31 products tested positive for at least one illegal component (sildenafil, tadalafil, propoxyphenyl, hydroxyhomosildenafil, or dimethylsildenafil).

J. Food Comp. Anal. 48, 25-33 (2016). HPTLC of kavalactones (K, DHM, DHK, M, DMY, Y) and flavokavins (FKA, FKB, FKC) in kava (Piper methysticum) on silica gel with hexane – dioxane 4:1. Individual standards of the following nine compounds of interest were applied on plates and scanned after elution to obtain their UV absorption maxima: flavokavin A (FKA, 361 nm), flavokavin B (FKB, 343 nm), flavokavin C (FKC, 368 nm), kavain (K, 247 nm), dihydromethysticin (DHM, 200 nm), dihydrokavain (DHK, 242 nm), methysticin (M, 306 nm), demethoxyyangonin (DMY, 338 nm), and yangonin (Y, 354 nm). Detection by dipping for 1 s into anisaldehyde – sulfuric acid reagent (10 mL sulfuric acid with 170 mL of ice-cooled methanol, 20 mL of acetic acid, and 1 mL of anisaldehyde reagent), followed by heating at 100 ºC for 3 min. Quality of the samples was assessed by computing two ratios after scanning the plates at 245 nm (kavain/total kavalactones; K/KL) and 366 nm (flavokavins/kavalactones; FK/KL). The ratio K/KL corresponds to the peak area of K versus the sum of the peak areas of all other kavalactones (DHM + DHK + M + DMY + Y). The ratio FK/KL corresponds to the sum of the peak areas of the three FK (A + B + C) versus the peak areas of Y and DMY._x000D_

Planta Medica 82(11/12), 1009-1015 (2016). _x000D_
To check the purity of six alkaloids isolated from fractions of a methanolic extract of Carapichea ipecacuanha, TLC on silica gel with dichloromethane – methanol – 25 % ammonia 186:13:1, detection with Dragendorffʼs reagent. By TLC comparison with standards (and confirmation by HPLC-MS), emetine (found to be a strong hERG potassium channel blocker) and N-methylemetine were identified._x000D_

Planta Medica 82 (16), 1438-1445 (2016). TLC on silica gel with chloroform – methanol 19:1, followed by detection under UV 254 nm and spraying with 10 % sulfuric acid with heating. TLC was used for 1) the ethyl acetate fraction of a hydromethanolic extract of Eryngium triquetrum aerial parts, and 2) for the monitoring of its fractionation on a cyclodextrin column, and of the fractionation of a selected fraction on silica gel column. The (chloroformic) first subfraction of the last step was found to contain only the polyyne alcohol falcarinol (panaxynol, carotatoxin) at hRF 90.

J. Ethnopharmacol. 193, 490-499 (2016). HPTLC of quercetin in the leaves of Ocimum basilicum on silica gel with toluene – ethyl acetate – formic acid 17:11:2. Quantitative determination by absorbance measurement at 254 nm.

Chinese J. of Drug Evaluation 32 (4), 193-194 (2015). Fortune Paulownia leaf, the dry leaf of Paulownia fortunei (Seem.) Hemsl, is a TCM raw material used for treatment of carbuncles, furuncles, trauma, hemorrhage, etc. For quality control, TLC of its extracts on silica gel previously impregnated with 1 % iodine in dichloromethane and developed with cyclohexane – ethyl acetate – glacial acetic acid 20:6:1, detection by spraying with 10 % sulfuric acid in ethanol and heating at 105 ºC until the zones are clearly visualized, viewing (A) in white light and (B) under UV 366 nm. Identification by fingerprint comparison with the standards oleanolic acid (hRf 67) and ursolic acid (hRf 60) and the reference raw material in parallel.

Planta Medica 83(01/02), 135-142 (2017). Preparative TLC on silica gel for the purification of recrystallized farnesiferol B (hRF 50; with petroleum ether – ethyl acetate 8:1) and sinkianol B (hRF 40; with chloroform – methanol 15:1) isolated through column chromatography from petroleum ether – dichloromethane fractions of the chloroform extract of Ferula sinkiangensis gum resin.

J. Planar Chromatogr. 30, 211-215 (2017). HPTLC of benzyl isothiocyanate in the root of Salvadora persica on silica gel with n-hexane ‒ ethyl acetate 9:1. Quantitative determination by absorbance measurement at 191 nm. The hRF value for benzyl isothiocyanate was 61. Linearity was between 100 and 600 ng/zone. The intermediate precision was below 2 % (n=3). Recovery ranged from 97.6 to 99.5 %.