J. Planar Chromatogr. 27, 52-57 (2014). HPTLC of paracetamol (1), dicyclomine hydrochloride (2) and mefenamic acid (3) on silica gel with toluene - ethyl acetate - methanol 6:3:1. Quantitative determination by absorbance measurement at 290 nm. The hRF values for (1) to (3) were 27, 41 and 61, respectively. Linearity was in the range of 600-1800 ng/zone for (1), 400-2400 ng/zone for (2) and 300-1500 ng/zone for (3). The intermediate/interday/intra-day precisions were below 2 % (n=3). The LOD and LOQ were 35 and 116 ng/zone for (1), 109 and 360 ng/zone for (2) and 42 and 140 ng/zone for (3), respectively. Recovery was in the range of 97.7-99.9 % for (1) to (3).

J. Planar Chromatogr. 28, 24-29 (2015). HPTLC of new derivatives of 1,2,4-triazole and thiosemicarbazide on RP-18W with 30 % acetonitrile and 40 % MeOH as organic modifiers, both in water, detection at UV 254 nm. 30 % provided the most close phase ratio in TLC and HPLC. The method can be used as a pilot technique for the anticipation of retention in HPLC.

J. Planar Chromatogr. 27, 444-448 (2014). HPTLC of quercetin in fresh tubers of Satyrium nepalense on silica gel with toluene – ethyl acetate – formic acid 7:5:1. Quantitative determination by absorbance measurement at 366 nm. The hRF value of quercetin was 54. Linearity was in the range of 2-12 μg/zone. The intermediate intra-day and inter-day precisions were below 1 % (n=3) for quercetin. The LOD and LOQ was 40 and 120 ng/zone, respectively. Mean recovery for quercetin was 99.8 %.

induces apoptosis and inhibits multi-drug resistance transporters in human epithelial cancer cells. J. Ethnopharmacol. 158, 33-42 (2014). HPTLC fingerprint of the whole plant of Vernonia cinerea L. on silica gel with toluene - ethyl acetate - formic acid 6:3:1, detection at UV 366 nm. The dichloromethane fraction showed the presence of 9 zones, including the standard lupeol at hRF 60.

J. Planar Chromatogr. 27, 372-376 (2014). For quality control, HPTLC of cefprozil monohydrate on silica gel with ethyl acetate – acetone – methanol – water – glacial acetic acid 15:5:5:3:1. Quantitative determination by absorbance measurement at 280 nm. The hRF value of cefprozil monohydrate was 20. Linearity was between 200 and 5000 ng/zone. The intermediate precision was below 1.5 % (n=3). The LOD and LOQ were 52 and 75 ng/zone, respectively. Recoveries were in the range of 98.7-101.2 %.

J. Liq. Chromatogr. Relat. Tech. 38, 381-389 (2015). Review of the materials, techniques and instruments for the detection and quantification of radiolabeled compounds by planar radiochromatography. Special reference is made to sample preparation, stationary phases (including instant TLCD sheets), initial zone application, mobile phases, stationary phase development, and zone detection and quantification.

J. Planar Chromatogr. 28, 213-217 (2015). HPTLC of (1) chlorogenic acid, (2) caffeic acid, (3) faradiol and (4) rutin from Calendula officinalis plant extracts on silica gel previously activated at 50 °C in an oven for 30 min. Automated multiple development (gradient elution) with n-hexane, ethyl acetate containing 2 % acetic acid, and water as mobile phase. Detection by spraying with either 10 % sulfuric acid in methanol or 2-aminoethyl diphenylborinate solution followed by placing in oven at 50 °C for 30 min. (1), (2), (3), and (4) were used as markers to investigate and assess the quantitative errors observed. Accuracy of the sample applicator at different sample volumes, the use of a gradient mobile phase, and post-derivatization contribute to uncertainties of the HPTLC method and need to be carefully selected to minimize errors.

In. Arch. Otorhinolaryngol. 19, 141-150 (2015). HPTLC of the lipids lactosylceramide (1), triacylglycerol (2), phosphatidylcholine (3), cholesterol (4) and sphingomyelin (5) in mastoid tissue on silica gel with chloroform - methanol - water 65:25:4. Detection of lipids by spraying with orcinol reagent (0.02 % in 50 % sulfuric acid) followed by heating at 120 °C for 2-3 minutes. Additional detection with Coomassie Brilliant Blue (0.03 % in 30 % methanol/100 mM sodium chloride) followed by methanol 30 % in 100 mM sodium chloride for destaining. The hRF value was 24-47 for (1) and (5), 71-100 for (2) and (4), and 0-24 for (3). Combination with gas chromatography/electron impact-mass spectrometry revealed the presence of cholesterol and several fatty acids. Combination with flow-injection/electrospray ionization-tandem mass spectrometry revealed a host of phosphatidylcholines, phosphatidylethanolamines, and cholesteryl esters.