J. Planar Chromatogr. 16, 289-292 (2003). HPTLC of 6 porphyrins (5,10,15,20-tetratolylporphyrin, 5-(4-methoxyphenyl)-10,15,20-tritolylporphyrin, 5,10-di(4-methoxyphenyl)-15,20-ditolylporphyrin, 5,15-di(4-methoxyphenyl)-10,20-ditolylporphyrin, 5,10,15-tri(4-methoxyphenyl)-20-tritolylporphyrin, 5,10,15,20-tetra(4-methoxyphenyl)-porphyrin) on diol modified silica gel with dichloromethane- ethyl acetate 97:3. Quantitation by densitometry at 420 nm. Convenient and accurate procedure.

Planta Medica 82,09/10, 910-918 (2016). After a fermentation process, the broths of psychrotolerant strains Vibrio splendidus T262 (isolated from the digestive tract of an Antarctic Ocean fish) and Arthrobacter psychrochitiniphilus T406 (found in penguin excrements in King George Island) were extracted with ethyl acetate and fractioned. To check the purification of new bisindole alkaloids from V. splendidus (turbomycines C-F) (1), and of A. psychr. (2-(indol-3-yl-methyl)indol-3-yl ethanol (2), TLC on silica gel (with water-resistant binders) with hexane – ethyl acetate 9:1 for (1) and dichloromethane – methanol 9:1 for (2). Evaluation before and after treatment with anisaldehyde reagent. Also preparative TLC on silica gel to isolate the following alkaloids from V. splendidus: monoindole: 4-(1H-indol-3-yl-sulfanyl)phenol (hRF 45 with hexane – ethyl acetate 17:3); bisindoles: 2,2-di-(3-indolyl)-3-indolone and 4-bis(1H-indol-3-yl)methyl]-cyclohexa-2,5-dienone (eluent not given); and trisindoles: trisindolal (hRF 58 with dichloromethane – methanol 9:1), metagenetriindole (hRF 45 with the same), and turbomycine A (not given).

J. Liq. Chromatogr. Relat. Technol. 33, 1038-1046 (2010). TLC of nicotinic acid and methyl, ethyl, isopropyl, butyl, hexyl, and benzyl nicotinate (heated for 1 to 7 h at 120 °C) on silica gel pre-washed with methanol using methanol - benzene (for nicotinic acid) and acetone - hexane 2:3 for nicotinic acid esters. Quantitative determination by densitometric absorbance measurement at the respective absorption maximums (263 nm for nicotinic acid, 220-222 nm for nicotinic acid esters). The hRf of nicotinic acid was 44, and of methyl, ethyl, isopropyl, butyl, hexyl, and benzyl nicotinate 48, 46, 51, 54, 56, and 44, respectively.)

Eurasian J. Anal. Chem. 4(1), 87-97 (2009). HPTLC of rabeprazole sodium on silica gel with acetone - water 7:30. The hRf value was 45. Densitometric quantification at 284 nm. Linearity was in the range of 400-2400 ng/band. The recovery was 99.6-101.4 %. The sample was subjected to forced degradation (acid, alkali, oxidative, thermal, photolytic). The degradation products were well separated from the main compound and the method is suitable for stability studies.

62nd Indian Pharmaceutical Congress Abstract No. F-262 (2010). TLC of carbamazepine on silica gel with ethyl acetate – toluene – methanol 5:4:1. Quantitative determination by absorbance measurement at 285 nm. The hRf value was 47. The linearity was in the range of 100-600 ng/zone with r2 = 0.9995. The limit of detection was found to be 17 ng/zone, whereas the limit of quantitation was found to be 50 ng/zone.

J. Planar Chromatogr. 27, 192-198 (2014). HPTLC of losartan (1), irbesartan (2), valsartan (3), and_x000D_ olmesartan (4) in plasma and dosage form on silica gel with chloroform - glacial acetic acid 3:1. Quantitative determination by absorbance measurement at 255 nm. The hRF values for (1) to (4) were 36, 45, 78 and 23, respectively. Linearity was in the range of 90-750 ng/zone for compounds (1) to (4). The intermediate/interday/intra-day precisions were below 3 % (n=6). The LOD and LOQ were 30 and 91 ng/zone for (1), 18 and 56 ng/zone for (2), 15 and 45 ng/zone for (3) and 30 and 92 ng/zone for (4), respectively. Recovery was between 96.4 and 99.5 % for (1) to (4).

Detection by spraying with 11 reagents. Application examples.

J. Chromatogr. 471, 407-419 (1989). Study of TLC retention behavior of a series of ß-carbolines on silica and amino-modified silica. Discussion of the retention mechanism in relation to different solute, solvent and stationary phase characteristics. Comparison of the stationary phases, TLC and HPLC techniques and various solvent selectivities. Study of the molecular structure-retention relationship by means of the group contributions to retention and the electronic constant.