CBS 110, 2-4 (2013). HPTLC of caffeic acid, chlorogenic acid, and rutin hydrate on silica gel (prewashed with methanol and dried under vacuum at 50 °C for 30 min) with formic acid - ethyl acetate - water - methyl ethyl ketone 5:30:6:18 with chamber saturation for 5 min over a developing distance of 5 cm. Detection under UV 254 nm. Elution of substance zones with TLC-MS Interface using methanol and a flow-rate of 0.3 mL/min for 6 min. Evaporation of methanol under nitrogen, residue taken up with methanol-d4. Subsequent off-line quantitative 1H-NMR spectroscopic analysis of the residue, acquisition time 30 min. Linearity for all substances was confirmed in the range of 10 - 80 µg/mL. Recoveries were in the range of 100.5 % for chlorogenic acid and up to 103.4 % for caffeic acid, with precisions under 3.9 % (%RSD, n=3).

J. Liq. Chromatogr. Relat. Technol. 36, 2497-2511 (2013). HPTLC evidence of rapid peptidization of L-proline and DL-proline on silica gel with 2-butanol - pyridine - ammonia (25 %) - water 39:34:10:26 and on silica gel plates impregnated with Mn(II) and Cu(II) acetate with dioxane - water 13:7+1 drop 2 % acetic acid. HPTLC enantioseparation of DL-proline was performed with 2-butanol - pyridine - glacial acetic acid - water 15:10:3:12. Detection by dipping into 0.5 % ninhydrin solution in 2-propanol, followed by heating for 2 min at 110 °C. Quantitative determination by absorbance measurement at 340 nm.

J. Planar Chromatogr. 25, 150-155 (2012). HPTLC of methocarbamol (1) and its related substance guaifenesin (2) in two ternary mixtures with ibuprofen (3) and diclofenac potassium (4) on silica gel with ethyl acetate - acetone - triethylamine 62:35:6 + 1 drop formic acid. Quantitative determination by absorbance measurement at 222 nm for the first mixture and 278 nm for the second mixture. The hRf values for agents (1) to (4) were 78, 54, 14 and 12, respectively. Linearity was in the range of 2-12 µg/band for (1), 2-10 µg/band for (2), 4-20 µg/band for (3) and 0.2-2.2 µg/band for (4). The intermediate/inter-day/intra-day precision was below 1.5 %. Mean recovery for (1) to (4) was between 100.7 and 100.8 %.

by thin-layer chromatography) (Chinese). J. of Guizhou Normal Univ. (Natural Sci.) 30 (3), 1-3 (2012). Kalimeris indica (Linn.) Sch. is a perennial herb used in TCM preparations for treating cold fever, hepatitis, parotitis, pharyngitis, indigestion, etc. For quality control, TLC on silica gel with chloroform – methanol 9:1, detection by spraying with 5 % sulfuric acid in ethanol and heating at 105 °C, viewing in daylgiht. The standard was alpha-spinasteryl-3-O-ß-D-glucoside.

J. Chromatogr. A 1260, 232-238 (2012). Presentation of a new RP-HPTLC method for the separation of pyrazinamide, isoniazid, rifampicin and ethambutol in a four fixed-dose combination tablet formulation by detection of pyrazinamide, isoniazid and rifampicin at UV 280 nm firstly, and then derivatization and detection of ethambutol at 450 nm after RP-plate development. Evaluation of methanol, ethanol and propan-1-ol as the modifiers to form alcohol-water mobile phases. Systematic optimization of the composition of each alcohol in the mobile phase by using the window diagramming concept to obtain the best separation. Examination of the Rf distribution of the separated compounds indicated that separation of the compounds with the mobile phase containing ethanol at the optimal fraction situated within the optimal hRf-values region of 20-80, thus ethanol was selected as the organic modifier and the optimal mobile phase composition was found to be ethanol – water - glacial acetic acid - 37 % ammonia 70:30:5:1.

J. Liq. Chromatogr. Relat. Technol. 36, 2363-2377 (2013). The impact of substituent of benzanilide moiety on retention of 14 (alkoxy-phenyl)benzamides was assessed by TLC on silica gel and aluminium oxide with various mixtures of n-pentane, benzene and acetone. The TLC method allowed for quantitative structure relationship (QSRR) studies with benzanilide derivatives.

J. Planar Chromatogr. 26, 267-273 (2013). HPTLC of glabridin in a Glycyrrhiza glabra formulation on silica gel with toluene - dichloromethane - ethyl acetate 1:1:1. Quantitative determination by absorbance measurement at 287 nm. The hRf value for glabridin was 57. Linearity was in the range of 25-500 ng/zone. LOD and LOQ were 10 and 25 ng/zone. Recovery was in the range of 97.3-103.2 %. Intermediate/interday/intra-day precision was below 2 % (n=6).

J. Planar Chromatogr. 26, 375-378 (2013). TLC of estrone, estradiol, and estriol on silica gel with chloroform - ethyl acetate - acetone 6:2:1. Detecion by dipping into (1) 10 % solution of phosphomolybdic acid (PMA) in methanol, followed by heating at 100 ºC for 10 min; (2) 0.2 % ceric ammonium sulfate in phosphoric acid, followed by heating at 110 ºC for 10 min; (3) 0.2 g manganese(II) chloride in 30 mL water, 30 mL methanol and 2 mL concentrated sulfuric acid, followed by heating at 100-120 ºC for 10-15 min; and (4) 1 g of vanillin in 25 mL of ethanol, 25 mL of distilled water, and 35 mL of ortho-phosphoric acid (85 %), followed by heating at 120-160 ºC for 5-15 min. The lowest detection limit for estrone (75 ng/zone) was achieved using (1) and (3), whereas for estradiol and estriol (both 4.7 ng per zone) by using (2).