Chromatographia 47, 529-536 (1995). 2D-TLC on silica gel with hexane - ethyl acetate 7:3 for the 1st direction and hexane - acetone for the 2nd. Identification by comparison of the retention values. Also HPLC and mass spectrometry.

J. Chinese Trad. Patent Med. (Zhongchengyao) 25 (7), 538-540 (2004). TLC on silica gel with 1) petroleum ether - ethyl acetate - butanone - methanol - water 15:25:3:7:1; 2) petroleum ether - ethyl acetate - formic acid 15:5:1. Detection 1) under UV light, 2) by spraying with 5 % potassium iodobismuthate solution and heating at 105 ºC for 5 min. Identification by finger print technique. Quantification of betaine by densitometry at 514 nm.

Acta Chrom. 11, 204-214 (2001). Electric fields have been shown to affect peak width, peak area, and other chromatographic properties in reversed-phase TLC on silanized silica gel and RP-18. To eliminate electroosmotic flow, thin layer electro-chromatography was performed on unwetted layers. Horizontal and vertical modes of thin-layer electrochromatography were investigated, but only for chromatographic systems in which van der Waals forces are the sole interactions. Analytes were polycyclic aromatic hydrocarbons and hexane or heptane was used as mobile phase. The electric field affects the chromatographic process not only by replacing capillary flow by electroosmotic flow.

LC-GC Europe 16, 2-5 (2003). Overview of utility of the technique for the identification and quantification of pharmaceutical compounds and related substances such as UK-137,457 (C31H31NO5) and UK-124,912 (C27H25NO3). Several of the issues that have arisen in the development of TLC-MALDI-MS methods for the successful analysis of pharmaceuticals were adressed in this article. Electrospray deposition method, which was found to be superior to other methods studied and was successfully applied to a range of compounds presented, concerns a method for the deposition of the MALDI matrix onto the TLC plate. Post-source decay analysis can be performed directly on the TLC spots, to aid in structural evaluation of the analyzed compounds. The generation of quantitative data using a structural analogue as internal standard and incorporation into the mobile phase has also been demonstrated. Outlook for next step development of TLC-MALDI-MS in pharmaceutical analysis for more widespread use in industry: enhance sensitivity, mass resolution and reproducibility, availability of commercial instruments that allow the scanning of whole TLC plates rapidly with data-imaging software.

J. Chromatogr. A 1216 (42), 7096-7101 (2009). Presentation of a TLC-blot–MALDI-IMS method which combines TLC and IMS (imaging mass spectrometry) for use in lipidomics. In comparison with common staining methods the method allows highly sensitive detecion of whole lipids and individual molecular species. Linearity for all lipids ranged approximately over one order of magnitude. Precision (%RSD) was <16 %. The TLC step allows precise separation of complex lipid mixtures into individual lipid classes before MS analysis is performed.

Rapid Commun. Mass Spectrom. 25, 2275-2282 (2011). The authors explored the possibility of the desorption at an angle scanning analysis of surfaces from direct analysis in real time mass spectrometry (DART-MS), including the coupling of planar chromatography with DART-MS. A method for the visualization of the impact region of the DART gas stream was developed, as well as the DART-MS detectability of liquids was increased, improving the capabilities of DART-MS in trace analysis.

J. Liq. Chromatogr. Relat. Technol. 37, 2892-2914 (2014). Study of the background mass signals derived from different solvents either used for prewashing or chromatography that may interfere in HPTLC-MS using the elution head-based TLC-MS Interface. Pre-washing of plates with methanol – water 3:1 reduced background signals to a minimum, but also special plates for MS are suited (plates of specified MS quality). The results showed that acidic solvents can cause intense background signals due to acid adduct cluster formations. The fluorescence indicator did not impact the mass spectra. It was shown that subtraction of background spectra (at a comparable migration distance) from the analyte mass spectrum is a helpful tool, especially in the case of cluster formation. Recommendations for general plate handling for use in TLC/HPTLC-MS were provided.

Planta Medica 82, 11/12, 1051-1057 (2016). The crude ethanol extract of the aerial parts of the liverwort Chiloscyphus polyanthos, its fractions and seven pungent sesquiterpene lactones isolated therefrom were analyzed against Candida albicans strains (hypersensitive mutant DSY2621, wild-type parent CAF2-1). 20 mL of C. albicans suspension were spread and solidified on the plate charged with samples (20 µg/spot), blank (methanol) or reference (miconazole); without any development, the plate was incubated overnight at 37 °C, sprayed with methyl thiazolyl tetrazolium chloride (MTT 0.25 %) and incubated for 6 h at 37 °C to obtain a purple background. Diplophyllolide A was active on both strains, four other lactones only on DSY2621 (l-diplophyllin, dihydrodiplophyllin, ent-3-oxodiplophyllin, 3β-hydroxyeudesma-4,11-dien-12,8α-olide)._x000D_