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: A simple, rapid, and reliable technique for identifying small amounts of phenylthiohydantoin (PTH) derivatives has been developed for use in the analysis by Edman degradation ofsmall amounts of peptides isolated from fingerprints.
291 citations
TL;DR: Improved techniques are further required to evaluate the CLA profile in monogastric animals fed commercial CLA preparations for CLA enrichment of animal products and to help design experimental diets to increase the level of the desired CLA isomers in dairy fats.
Abstract: Conjugated linoleic acids (CLA) are octadecadienoic acids (18:2) that have a conjugated double-bond system. Interest in these compounds has expanded since CLA were found to be associated with a number of physiological and pathological responses such as cancer, metastases, atherosclerosis, diabetes, immunity, and body fat/protein composition. The main sources of these conjugated fatty acids are dairy fats. Rumen bacteria convert polyunsaturated fatty acids, especially linoleic and linolenic acids, to CLA and numerous trans- containing mono- and diunsaturated fatty acids. It has been established that an additional route of CLA synthesis in ruminants and monogastric animals, including humans, occurs via delta9 desaturation of the trans-18:1 isomers. To date, a total of 6 positional CLA isomers have been found in dairy fats, each occurring in 4 geometric forms (cis,trans; trans,cis; cis,cis; and trans,trans) for a total of 24. All of these CLA isomers can be resolved only by a combination of gas chromatography (GC), using 100 m highly polar capillary columns, and silver-ion liquid chromatography, using 3 of these 25 cm columns in series. Complete analysis of all the trans-18:1 isomers requires prior isolation of trans monoenes by silver-ion thin-layer chromatography (TLC), followed by GC analysis using the same 100 m capillary columns operated at low temperatures starting from 120 degrees C. These analytical techniques are required to assess the purity of commercial CLA preparations, because their purity will affect the interpretation of any physiological and/or biochemical response obtained. Prior assessment of CLA preparations by TLC is also recommended to determine the presence of any other impurities. The availability of pure CLA isomers will permit the evaluation and analysis of individual CLA isomers for their nutritional and biological activity in model systems, animals, and humans. These techniques are also essential to evaluate dairy fats for their content of specific CLA isomers and to help design experimental diets to increase the level of the desired CLA isomers in dairy fats. These improved techniques are further required to evaluate the CLA profile in monogastric animals fed commercial CLA preparations for CLA enrichment of animal products. This is particularly important because absorption and metabolism will alter the ingested-CLA profile in the animal fed.
287 citations
TL;DR: Application of this one-dimensional two-step thin-layer Chromatographie system for separation of classes of neutral lipids on silica gel without CaSO4 binder in rat liver and in human serum is demonstrated.
287 citations
TL;DR: Eight novel heterocyclic Schiff bases derived from the condensation reactions of indole 3-carboxaldehyde with different l-amino acids as well as with some aminophenols, have been synthesized and characterized by various spectroscopic methods.
285 citations
TL;DR: In this article, a method for the analysis of isomeric monoglycerides by thin-layer adsorption chromatography was developed for the separation of 1-and 2-monoglyceride.
Abstract: A method has been developed for the analysis of isomeric monoglycerides by thin-layer adsorption chromatography Isomeric monoglycerides are separated on silica gel impregnated with boric acid; a mixed solvent system is used The interaction of hydroxy compounds with boric acid allows the separation of 1- and 2-monoglycerides which cannot be resolved on silica gel alone In order to make the method quantitative, the resolved components are charred and their spot densities measured Glycerol, fatty acids, diglycerides, and triglycerides do not interfere The method does not induce isomerization
283 citations