Phytochem. Anal. 22, 258-262 (2011). TLC of gomisin A (1), gomisin N (2) and schisandrin (3) in the fruits of Schisandrae chinensis on silica gel with toluene - ethyl acetate - formic acid 14:6:1. Quantitative determination by direct analysis in real time mass spectrometry (DART-MS). Linearity of (1) - (3) was between 0.5 and 5 nmole. The limits of detection and quantification were 60-200 pmole for (1), and 58-192 pmole for (2) and (3). Recovery (by standard addition) for (1) - (3) was between 104.0 and 120.2 %. TLC-DART-MS method provides faster and more specific quantification compared with the conventional densitometric and HPLC-UV methods.

J. of China Three Gorges Univ. Natural Sciences 33 (4), 92-95 (2011). TLC of extracts of Biyuan Pills on silica gel 1) for Magnolia liliiflora Desr. with dichloromethane - ethyl acetate 9:1, detection by spraying with 10 % sulfuric acid in ethanol and heating at 90 °C until the zones were detected; 2) for Xanthium sibiricum Patr., with chloroform - ethyl acetate - methanol - water - formic acid 3:10:2:2:2, detection by exposure to iodine vapor until the zones were detected; 3) for Lonicera japonica and Chrysanthemum indici flos, with toluene - ethyl acetate - formic acid - glacial acetic acid - water 1:15:1:1:2, detection under UV 365 nm.

J. of China Pharm. 21 (4), 30-31 (2012). Shenqixinjikang compound oral liquid, as a TCM preparation is specially effective for invigorating the circulation of blood, inducing resuscitation, relieving pain, and is prescribed clinically to cure cardiopalmus and angina pectoris. For quality control, TLC of the extracts of the medicine 1) for Rhizoma Polygoni Cuspidati, on silica gel with petroleum ether ( 60-90 ºC) – formyl acetate – formic acid 15:5:1, detection at UV 366 nm; 2) for Leguminosae, on silica gel with n-butanol – acetic acid – water 5:1:4, detection by spraying with 10 % sulfuric acid in ethanol and heating at 105 °C for 5 min followed by evaluation under daylight or UV 366 nm; 3) for Rehmannia, on silica gel with chloroform – methanol – water 14:6:1, detection by spraying with 3 % vanillin in ethanol – sulfuric acid 100:1 and heating at 105 °C followed by evaluation under daylight.

J. Planar Chromatogr. 26, 445-451 (2013). HPTLC of telmisartan (1) and atorvastatin (2) on silica gel with methanol - chloroform 1:7. Quantitative determination by absorbance measurement at 280 nm. The hRf values for (1) and (2) were 64 and 27, respectively. Linearity was between 1.2-7.2 µg/zone for (1) and 0.4-2.4 µg/zone for (2). LOD and LOQ were 3 and 8 ng/zone. Recoveries (by standard addition) were 98-101 % for (1) and 99-101 % for (2). Intermediate intra- and inter-day precision was below 2 %. Comparable results were obtained with HPLC and UV methods.

J. Planar Chromatogr. 27, 333-339 (2014). TLC of alkaloids such as (1) papverine, (2) quinine, (3) berberine, (4) brucine, (5) emetine, (6) chelidonine, (7) boldine, (8) protopine and (9) allocryptopine on CN or RP18W phase with mixture of acetonitrile and water containing: acetic buffer at pH 3.6, 1 % acetic acid, 1 % ammonia, 0.01 M octane sulfonic acid sodium salt or methanol, and water containing 0.01 M diethylamine. On C18 plates, the best conditions for the separation of alkaloids were obtained with the mobile phase containing addition of octane sulfonic acid sodium salt, diethylamine, or aqueous ammonia; as for the CN plates, with aqueous eluents containing diethylamine or ammonia and nonaqueous eluent containing mixture of methanol, diidopropyl ether, and 2% ammonia. The efficiency of the system was increased by using a combination of two-dimensional thin-layer chromatography with multiple development chromatogram methods.

Food Chem. 239, 865-871 (2018). NIR spectroscopy for the analysis of oleic, palmitic, linoleic, linolenic, omega-3 and omega-6 acids, unsaturated and saturated fatty acids, and triacylglycerides was compared with HPTLC and GC methods. HPTLC of polar (1) and neutral (2) lipids in salmon oil on silica gel with methyl acetate – isopropanol – chloroform – methanol – potassium chloride (0.25 % solution) 25:25:25:10:9 for (1) and with n-hexane – diethyl ether – glacial acetic acid 35:15:1. Detection by dipping into primulin reagent (10 mg primuline, 40 mL water, 160 mL acetone) for 2 s. The NIR method permits the simultaneous quantification of several fatty acids, but the accuracy and robustness of the method remain at the screening level for palmitic and linolenic acids and monounsaterated fatty acids. The method is not sensitive enough to detect low concentrations of fatty acids, therefore direct measurements on salmon tissue samples were not considered. The NIR method requires a previous extraction of the lipids, similar to the chromatographic techniques. Still the NIR method is a fast, direct and not destructive technique for salmon oil sample screening purposes.

J. Chromatogr. Sci., 56 (9), 846–852 (2018). Simultaneous determination of theophylline (THP), guaifenesin (GUI) and guaiacol (GUA, a guaifenesin impurity) by HPTLC on silica gel with ethyl acetate – hexane – methanol - ammonia 65:35:10:2. Detection and quantification by densitometry at 275 nm. The hRf values were 13, 35 and 80 for THP, GUI and GUA, respectively. The linearity range was 0.4–2 μg/band for both THP and GUI, and 0.4–1.2 μg/band for GUA. Validation of the proposed method according to ICH guidelines. Statistical comparison of the results with RP-HPLC showed no difference regarding accuracy and precision.

(Hungarian). (N-demethylation of morphine alkaloids III. Some new reactions of the N-demethyl derivatives.). TLC on silica with benzene - methanol 8:2, chloroform - methanol 9:1 and chloroform - acetone - diethylamine 5:4:1. Visualization by UV or by Dragendorff reagent. Identified substances: N-demethylneopine, N-demethylneomorphine.