Chinese J. of Spectroscopy & Spectral Anal. 34 (4), 990-993 (2014). In recent years, some frauds were discovered on the drug market, e.g. chemical drugs with similar effect were illegally added to herbal TCM for hypertension which may cause a variety of adverse reactions and even endanger life. To ensure the safety of patients a method is presented for rapid screening of antihypertensive drugs. TLC on silica gel with dichloromethane – methanol – water 90:10:1, detection under UV 254 nm. Identification of nicardipine hydrochloride, doxazosin mesylate, propranolol hydrochloride and hydrochlorothiazide by comparison of the corresponding hRf values of standards. Qualitative analysis of the sample target zones by adding a few drops of silver glue solution onto each zone and then detection by surface enhanced Raman spectroscopy (SERS) using a portable Raman spectrometer at the integration time of 10 s and the laser power of 100 mW with a minimum detection amount of 5, 5, 50 and 50 ng, respectively. The TLC method was optimized regarding mobile phase, sample application volume, the concentration of silver glue solution, etc. The method was used for the analysis of 10 commercial products from the drug market. Two products contained illegally added nicardipine hydrochloride and doxazosin mesylate, and one product contained propranolol hydrochloride and hydrochlorothiazide.

by the combination of high-performance thin-layer chromatography with direct bioautography and mass spectrometry. J. of Chromatogr. A 1422, 310-317 (2015). Investigation of two tansy (Tanacetum vulgare L.) essential oils, obtained by steam distillation of the capitula with subsequent liquid-liquid extraction (oil 1) or with use of an auxiliary phase for the trapping of the steam components (oil 2), against Bacillus subtilis F1276, B. subtilis spizizenii (DSM 618), Xanthomonas euvesicatoria, Pseudomonas syringae pv. maculicola, Ralstonia solanacearum strain GMI1000 and Aliivibrio fischeri by using the coupling of HPTLC to direct bioautography (HPTLC-DB). Oil 2 was richer in components and provided more inhibition zones due to the advanced extraction process. Identification of the main bioactive components by scanning HPTLC-direct analysis in real time mass spectrometry (HPTLC-DART-MS) and solid-phase microextraction GC electron impact MS (SPME-GC-EI-MS) as cis- and trans-chrysanthenol as well as trans-chrysanthenyl acetate. The results indicated that cis-chrysanthenol exhibited antibacterial effects against all tested bacteria. Trans-chrysanthenol inhibited B. subtilis, R. solanacearum and A. fischeri, and trans-chrysanthenyl acetate was an inhibitor for X. euvesicatoria, R. solanacearum and A. fischeri. However, the ionization characteristics and the recorded mass spectra showed that DART is a softer ionization technique than EI and more affected by ambient conditions and thus prone to additional oxidation products, although HPTLC-DART-MS resulted in a comparable fragmentation.

Planta Medica 83(03/04), 300-305 (2017). Preparative TLC on 1) RP-18 phase with methanol – water, in several proportions from 2:1 to 9:11 and on 2) silica gel with dichloromethane – ethyl acetate, from 5:1 to 10:3 was applied to purify eight phenylethylchromones from subfractions of a methanolic extract of Aquilaria filaria agarwood. Preparative TLC on silica gel with n-hexane – ethyl acetate 2:1 was also used to separate the products of one of these chromones (2-(2-hydroxy-2-phenylethyl)-4H-chromen-4-one) with the (S)- and (R)-MTPA-Cl (α-methoxy-α-trifluoromethyl-phenylacetyl-chloride) needed for the Mosher ester method for asymmetric carbon configuration, allowing, after NMR, the determination of the chromone as an uneven mixture of R- and S-enantiomers (4:1). The enantiomer separation was done after derivatisation into diastereoisomers (no chiral separation).

J. Sep. Sci. 41, 4387-4393 (2018). A new separation layer for TLC plates was developed for the separation in thin layers and direct conjugation to matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) without additional sample preparation. Best results were obtained with layers containing 19 to 29 % glycidyl methacrylate in the initial polymerization mixture.

J. Biochem. (Tokyo) 98, 265-268 (1985). New detection method; detection limit 1 mg; mass spectroscopy after elution.

J. Chromatogr. 369. 227-230 (1986). TLC for separation, detection and characterization of trace levels of porphyrins e.g., Ni uroporphyrin, Cu uroporphyrin and Ni protoporphyrin dimethyl ester. Application of Raman resonance spectroscopy. Comparison of the Raman spectra obtained from planar surfaces with spectra in solution. Discussions of the advantages and disadvantages of the technique. Metallo porphyrins, TLC/resonance Raman spectroscopy.

1. Direct analysis of conjugates by thin-layer chromatography-secondary-ion mass spectrometry. J. Chromatogr. 414, 139-148 (1987). Description of a method for direct molecular-secondary-ion mass spectrometry measurement of conjugates of p-nitrophenol and 4-hydroxyanti-pyrine following TLC on silica with butanol - acetic acid - ethanol - water 3:1:1:1. Discussion of the quantitative application using deuterium-labelled internal standards for p-nitrophenol conjugates.

J. Chromatogr. 450, 448-451 (1988). Investigation of the reaction products of lipase-catalyzed esterification and interesterification of lipids by TLC on silica containing 5% sodium carbonate with ether - hexane - methanol 60:40:3. Determination by toluene scintillation counter after scraping.