f. J. Planar Chromatogr. 27, 251-254 (2014). HPTLC of arnebin-1 in the roots of Arnebia nobilis on silica gel with toluene - ethyl acetate - formic acid 80:19:1. Quantitative determination by absorbance measurement at 284 nm. The hRF value for arnebin-1 was 65. Linearity was in the range of 2.5-20 μg/zone. The intermediate/interday/intra-day precisions were below 5 % (n=3). The LOD and LOQ were 14 and 48 ng/zone, respectively. Average recovery was 92.0 %.

J. Planar Chromatogr. 28, 144-151 (2015). TLC of L-cysteine on cellulose phase with 2-butanol - pyridine - glacial acetic acid - water 5:10:3:12. Just before development an equimolar amount of (1) manganese(II) acetate or (2) zinc(II) nitrate was added to the sample solutions. Detection in reflectance mode at 485 nm, concentration of L-cysteine and DL-cysteine in 70 % aqueous acetonitrile was 0.7 mg/mL. Developing distance was 7 cm, development time ca. 3 h. Derivatization by spraying with 0.5 % ninhydrin solution in 2-propanol, followed by heating for 5 min at 110 °C. The experiments demonstrate the spontaneous chiral conversion and spontaneous peptidization of L-cysteine, and the enantioseparation of L-cys and D-cys enantiomers is facilitated by chelating the transition metal cation (e.g. Mn(II)) with the cys ligands.

J. Chromatogr. Sci. 52 (9), 1089-1094 (2014). HPTLC of the anticancer compound nimbolide in different parts of Azadirachta indica and its dosage form on silica gel with n-hexane – ethyl acetate – acetic acid 30:20:1 (migration distance 68 mm, chamber saturation time 2 min), detection by spraying with 5 % sulfuric acid in methanol, quantification after absorption measurement at 515 nm. Validation by investigation of the (A) hRf value of nimbolide (43), (B) linearity range (200–1400 ng/zone, r2=0.99968), (C) LOD (70 ng/zone) and LOQ (200 ng/zone), (D) recovery (97.5 %, n=3), and (E) specificity (comparison of hRf value and UV/vis absorption spectrum with the standard).

J. Chromatogr. Sci. 56 (1), 92-98 (2018). TLC for direct enantiomeric resolution of the racemic β-adrenolytics bisoprolol (1), atenolol (2), propranolol (3), salbutamol (4) and carvedilol (5) by TLC using bovine serum albumin (BSA) as chiral additive in the stationary phase and with different compositions of simple organic solvents without buffer or inorganic ions. Systematic investigation of the effect of variation in pH, temperature, amount of BSA as the additive, and composition of mobile phase on resolution. Detection by exposure to iodine vapors. The five entantiomers were separated in the elution order (1), (2), (3), (4), and (5). The LOD was 0.7, 1.2, 0.8, 1.6 and 0.9 μg/zone for (1), (2), (3), (4), and (5), respectively.

Don using a validated high-performance thin-layer chromatographic method. J. Planar Chromatogr. 31, 220-229 (2018). Quantitative TLC of betulin (1), lupeol (2), oleanolic acid (3), and betulinic acid (4) in the bark, leaves, and roots of Betula utilis on silica gel with n-hexane ‒ ethyl acetate 4:1 for (1) to (3), and with toluene – ethyl acetate 7:3 for (4). (1) to (3) were detected by dipping into ceric ammonium sulfate reagent, followed by heating at 105–110 °C for 5 min. Compound (4) was detected by spraying with Liebermann‒Burchard reagent, followed by heating at 105–110 °C for 5 min. Quantitative determination by absorbance measurement at 500 nm for (1) to (3) and 550 nm for (4). The hRf values for (1) to (4) were 59, 71, 48 and 71, respectively. Linearity was in the range of 2.5-10 μg/zone for (1) to (4). The intermediate precision was below 4 %. The LOD and LOQ were 175 and 532 ng/zone for (1), 166 and 504 ng/zone for (2), 396 and 1201 ng/zone for (3) and 109 and 330 ng/zone for (4), respectively. Average recoveries for (1) to (4) were 98.9, 99.3, 99.3 and 99.2 %, respectively.

J. Liquid Chromatogr. 1227-1238 (1983). HPTLC of lactose and/or sucrose on silica with 1-butanolacetic acid - water 40:50:7.5, and of soya oil with petrol ether - ether - acetic acid 135:15:1.5. Detection of sucrose/lactose with 2 ml aniline + 2 g diphenylamine + 10 ml phosphoric acid + 88 ml CH3OH. For soya oil with ammoniummolybdate.

Proc. Intern. Symposium on TLC with special Emphasis on OPLC, Szeged, 15 (1984). OPLC (OPTLC) of atropine, scopolamine, scopoline, tropine, apoatropine on silica with a) isoamyl alcohol - propanol - chloroform- 0.1 M CH3COONa in water 7:23:5:5, b) butanol - methanol - chloroform - 0.1 M CH3COONa in water 8:12:5:5. Detection with Dragendorff reagent. Densitometry by absorbance at 400 nm.

Chromatographia 18, 253-259 (1984). HPTLC of antiarrhythmic drugs on silica with benzene - ethyl acetate - methanol - triethylamine 7:6:1:1 and of chloramphenicol on silica with heptane - chloroform - methanol 6:12:3. Densitometry by absorbance at 265 nm or by fluorescence for the former and by absorbance at 280 nm for the latter. Method for monitoring of therapeutic drugs in blood serum. Comparison with EMIT and HPLC.