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.

J. Planar Chromatogr. 28, 316-322 (2015). HPTLC of pyridostigmine bromide in pharmaceutical formulations on silica gel with methanol - ethyl acetate - triethyl amine - glacial acetic acid 180:20:10:1. Quantitative determination by absorbance measurement at 270 nm. The hRF values for pyridostigmine bromide and its alkaline degradation product were 14 and 34, respectively. Linearity was in the range of 2-10 ng/zone. LOD and LOQ were 1.9 and 0.6 ng/zone, respectively. The intermediate precision was 0.8 % (n=9). Recoveries ranged between 98 and 100 %.

Rapid Commun. Mass Spectrom. 30, 321-332 (2016). The paper describes different technical and methodic improvements for interface configuration, source caps and transfer tube to enhance sensitivity and reliability in Direct Analysis in Real Time mass spectrometry (DART-MS) surface scanning. By doing so, the detectability of HPTLC-scanning DART-MS was increased by a factor of 34, which is crucial for analysis in the low-nanogram range on the plate and the hyphenation of HPTLC with DART-MS, but also for surface scanning in general. The modified device was shown to work highly quantitative.

Rapid Commun. Mass Spectrom. 29, 1288-1296 (2015). HPTLC of sphingomyelins (1), phosphatidylcholines (2) and phosphatidylethanolamines (3) on silica gel with chloroform - methanol - water - acetic acid 30:15:2:4 for the first step and acetone - acetonitrile - chloroform 5:4:2 for the second step. Detection by spraying with 0.5 % amido black 10B stain in 1 M NaCl. The method was coupled with matrix-assisted laser desorption/ionisation mass spectrometry for the analysis of (1) and (2) extracted from 5,6-dimethylxanthenone-4-acetic acid-treated xenograft tumours.

Acta Scientiarum 37, 367-374 (2015). HPTLC of ochratoxin A from Aspergillus carbonarius on silica gel with ethyl acetate - toluene - 90 % formic acid 5:4:1. Qualitative determination under UV light at 366 nm.

Food Control. 68, 310-329 (2016). Review of the methodologies to determine the occurrence of aflatoxin M1 (AFM1) and the fate of AFM1 during processing of milk and dairy products, such as yoghurt and cheeses, since 1996 until today. The review describes the application of TLC and HPTLC in raw and pasteurized milk, feta cheese, yoghurt, white cheese, ice cream and butter.