Topic
Thin-layer chromatography
About: Thin-layer chromatography is a research topic. Over the lifetime, 7494 publications have been published within this topic receiving 124179 citations. The topic is also known as: TLC.
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TL;DR: Micro-analytical techniques used to study the lipid compositions of samples of skin from seven Dutch bog bodies showed that, while phospholipids have been degraded, other acyl lipids, for example triacylglycerols and steryl esters, may remain intact.
Abstract: A combination of micro-analytical techniques including thin layer chromatography (TLC), gas chromatography (GC). and combined gas chromatography/mass spectrometry (GCIMS) have been employed to study the lipid compositions of samples of skin from seven Dutch bog bodies. TLC showed that, while phospholipids have been degraded, other acyl lipids, for example triacylglycerols and steryl esters, may remain intact. GC and GC/MS analyses, following treatment of the total lipid extracts with acidified methanol, showed the presence of abundant fatty carboxylic acids and sterols. Molecular analysis by GC/MS allowed distinctions to be drawn between components originating from the bog body and the surrounding peat. Additionally, substances derived from microbial alteration of endogenous skin lipids and from the lipids of the micro-organisms themselves can be distinguished.
32 citations
TL;DR: Two-dimensional thin layer chromatography of 16 flavonoids and 3 phenolic acids was performed in normal and reversed phase systems on plates with chemically bonded-cyanopropyl stationary phase.
Abstract: Two-dimensional thin layer chromatography of 16 flavonoids and 3 phenolic acids was performed in normal and reversed phase systems on plates with chemically bonded-cyanopropyl stationary phase. TheR M values in some non-aqueous and aqueous systems were utilized to optimize separation.R M values were correlated for all investigated chromatographic systems and then optimum pairs of systems were selected for use in two-dimensional TLC separations.
32 citations
TL;DR: In this paper, a coal tar pitch from the high temperature coking of coal has been fractionated by planar chromatography into fractions immobile in pyridine, mobile in pyrolysis-gas chromatography/mass spectrometry at 770 and 1300°C, and by nuclear magnetic resonance (NMR) methods (1H in solution and 13C (CPMAS TOSS) in the solid state).
Abstract: A coal tar pitch from the high temperature coking of coal has been fractionated by planar chromatography into fractions immobile in pyridine, mobile in pyridine but not mobile in acetonitrile, and mobile in both solvents. Fractions have been examined by pyrolysis-gas chromatography/mass spectrometry at 770 and 1300 °C, and by nuclear magnetic resonance (NMR) methods (1H in solution and 13C (CPMAS TOSS) in the solid state). The fraction mobile in both solvents resembled the whole pitch in that the pyrolysis products were all polycyclic aromatics. The fraction mobile only in pyridine and the immobile fraction both gave alkene fragments as the most abundant pyrolysis products with polycyclic aromatics of low intensity only. The pyridine mobile and immobile fractions were shown by size exclusion chromatography with ultraviolet (UV) absorbance detection and by UV fluorescence spectroscopy to consist of large aromatic clusters and of large molecules. It is likely that the large aromatic clusters did not pyrolyse into fragments able to pass through the GC column. NMR methods confirmed the apparent trend of increasing aliphatic content with increasing immobility in thin layer chromatography. Copyright © 1999 John Wiley & Sons, Ltd.
32 citations
TL;DR: There are significant differences not only in fatty acid distributions of acyl lipids but also in molecular species of TAGs among the three cultivars, suggesting that the differences in pumpkin cultivars could be appreciable, based on the distribution of molecular species in TAGs.
Abstract: The lipids extracted from the kernels of pumpkin (Cucurbita spp) seeds of three cultivars were classified by thin layer chromatography into six fractions: steryl esters (SEs, 0.5–1.2%), triacylglycerols (TAGs, 92.7–93.4%), free fatty acids (FFAs, 2.9–3.5%), sn-1,3-diacylglycerols (1,3-DAGs, 0.4–0.9%), sn-1,2-diacylglycerols (1,2-DAGs, 0.7–0.9%) and phospholipids (PLs, 1.5%). Fatty acids derivatised as methyl esters were analysed by gas chromatography with flame ionisation detection. Molecular species and fatty acid distributions of TAGs, isolated from the total lipids in the kernels, were analysed by a combination of argentation thin layer chromatography (TLC) and gas chromatography. A modified argentation TLC procedure, developed to optimise the separation of the complex mixture of total TAGs, provided 11 different groups of TAGs, based on both the degree of unsaturation and the total chain length of fatty acid groups. With a few exceptions, SM2 (5.8–20.1%), S2D (8.8–11.2%), M3 (6.7–24.8%), SMD (6.8–16.7%), M2D (16.7–23.6%), SD2 (4.6–15.1%) and MD2 (4.9–18.6%) were the main TAG components. These results suggest that there are significant differences (P < 0.05) not only in fatty acid distributions of acyl lipids but also in molecular species of TAGs among the three cultivars. The differences in pumpkin cultivars could be appreciable, based on the distribution of molecular species in TAGs. However, pumpkin seed kernels could be utilised successfully as a source of edible oils for human consumption. Copyright © 2004 Society of Chemical Industry
32 citations
TL;DR: The properties, apparatus and applications of overpressured thin-layer chromatography (OPTLC) have been reviewed and examples of separations of mixtures have been given.
32 citations