J. Planar Chromatogr. 28, 74-82 (2015). HPTLC of two binary mixtures containing (1) omeprazole with (2) ketoprofen (mixture A) and (3) esomeprazole with (4) naproxen (mixture B) on silica gel with chlorofom - ethylacetate 3:7. Quantitative determination by absorbance measurement at 302 nm. The hRF values of (1) to (4) were 21, 49, 22 and 65, respectively. Linearities were between 30 and 300 ng/zone for (1) and (3), between 200 and 2000 ng/zone for (2) and between 500 and 6000 ng/zone for (4). The intermediate intra-day and inter-day precisions were below 2 % (n=3). The LOD and LOQ were 10 and 30 ng/zone for (1) and (3), 30 and 100 ng/zone for (2) and 150 and 500 ng/zone for (4), respectively. Recoveries for (1) to (4) ranged between 98 and 102 %.

Chinese J. Northern Pharm. 10 (12), 10-11 (2013). Yinhuang Qingre Jiaonang capsule is a TCM compound used for the treatment of respiratory tract infection, acute and chronic tonsillitis, sore throat, pneumonia, periodontitis, conjunctivitis, influenza virus infection, etc. For the quality control, HPTLC of the drug and berberine hydrochloride on silica gel (1) for Cortex Phellodendri Chinensis and Coptis chinensis Franch. with benzene – ethyl acetate – isopropanol – methanol – concentrated ammonia 12:6:3:3:1, detection by exposure to ammonia vapor; (2) for Flos Lonicerae Confusae with butyl acetate – formic acid – water 14:5:5; (3) for Fructus Aurantii (A) with ethyl acetate – formic acid – water 100:17:13 up to 3 cm, and then, (B) with toluene - ethyl acetate – formic acid – water 20:10:1:1 up to 8 cm; for all (1-3), detection at UV 366 nm. The method had been applied routinely and proved to be suited for the quality control of the medicine.

Food Chem. 187, 460-468 (2015). HPTLC-direct bioautography of bioactive compounds in the extracts of cold-pressed hemp (1), flax (2) and canola (3) seed oil on silica gel with toluene - ethyl acetate - formic acid - water 15:30:5:3 for (2) and toluene - ethyl acetate - acetic acid 80:25:4 for (1) and (3). HPTLC-DPPH scavenging activity was determined by dipping into a methanolic DPPH solution, followed by drying for 90 s in the dark and heating at 60 °C for 30 s. The hRF values of dominant radical scavenging zones were in the range of 75-85 for (1), 70-90 for (2) and 64 and 95-100 or (3). HPTLC-antimicrobial Aliivibrio fischeri assay allowed the determination of major antimicrobial zones at hRF 40-49 and 55-66 or (1), 23, 45 and 60 for (3) and 95 for (2). Additional effect-directed analyses employing acetylcholinesterase (AChE) assay, planar yeast estrogen (pYES) bioassay and Bacillus subtilis bioassay as well as subsequent HPTLC-ESI-MS allowed targeted characterization of bioactive compounds.

J. Planar Chromatogr. 28, 162-166 (2015). HPTLC of (1) sucrose, (2) glucose, (3) fructose, (4) arabinose, (5) cellobiose, (6) maltose, (7) mannose, (8) melezitose, (9) melibiose, (10) raffinose, (11) rhamnose, (12) stachyose, (13) trehalose and (14) xylose on silica gel with n-butanol - i-propanol - boric acid solution - formic acid 50:130:55:1 to a migration distance of 60 mm. Detection under white light after immersion into aniline diphenylamine o-phosphoric acid reagent and heating at 110 °C for 10 min. Qualitative detections were performed under white light and by absorption measurement at 380 nm. A total of 131 samples were analyzed with regard to their individual sugar composition and classified according to their sugar ratios.

J. Chromatogr. A 1390, 103-111 (2015). HPTLC-Vis-ESI-MS of 6 dyes in a commercially available dye mixture on silica gel with toluene up to a migration distance of 60 mm. Detection under white light and absorbance measurement using a multi-wavelength scan at 450, 500, 530 and 620 nm. Via the TLC-MS Interface the dye zones were eluted with methanol - ammonia formiate buffer (10 mM, pH 4.8) 19:1 at a flow rate of 0.1 mL/min into a single quadrupole mass spectrometer. Electrospray ionization mass spectra were recorded in full scan mode. Characteristic m/z values of dyes were used for quantitative measurements in SIM mode. The mean precisions (n=5) were below 10 % and a mean correlation was of 0.9975 for the 6 dyes. HPTLC-MS analysis revealed the incorrect assigment of components in two commercially available dye mixtures. Photooxidation degradation products were observed for interrupted workflows (for elutions after several days when the plate was kept in daylight).

Rapid Commun. Mass Spectrom. 29, 1242-1252 (2015). The paper describes the application of adding neon into helium for Direct Analysis in Real Time (DART) leading to plasma glow visualization to track the metastable gas distributions during surface scanning. The method allows for optimal selection of the coordinates for DART-MS analysis without loss in signal intensity. Visualization of the impact region of the excited gas stream is of high importance for further developments of planar chromatographic hyphenations with DART-MS.

J. Agric. Food Chem. 63, 9764-9769 (2015). HPTLC of the reaction products of 4-nitrophenyl β-D-glucoside (4NPGlc) with oleic acid, linoleic acid, and purified rice bran substrate catalyzed by rice transglucosidase Os9BGlu3 on silica gel with chloroform - methanol - 30 % ammonia 35:14:1. Detection by spraying with 10 % sulfuric acid in ethanol, followed by heating at 110 °C. The hRF value for the glucosyl conjugate was 53.

J. Liq. Chromatogr. Relat. Technol. 38, 1499-1506 (2015). RP-HPTLC of piperazine in pharmaceutical formulations on RP-18 with acetonitrile - water 3:2 modified with 1.5 % tetrafluoroborate. Quantitative determination by absorbance measurement at 247 nm. The hRF value for piperazine was 43. Linearity was in the range of 0.8-2.2 μg/zone. LOD and LOQ were 0.11 and 0.34 μg/zone. The intermediate precision was below 3.5 % (n=3). Recovery was between 99 and 103 %. Significant changes and improvements regarding the hRF value were observed when tetrafluoroborate was added to the mobile phase.