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.

Structure of methylpheophorbide-rci*

Abstract: he methanolic extract of the cyanobacterium (blue-green alga) Spirulina geitleri has been treated with methanolic acid to convert all chlorophyllous pigments to their methylpheophorbides. Fractionation of the latter from methylpheophorbide a by thin layer chromatography and high pressure liquid chromatography yielded methylpheophorbide-RCI. Its structure has been determined as 132S-hydroxy-20-chloro-methylpheophorbide a by 1H-nuclear magnetic resonance, absorption and circular dichroism spectroscopy, mass spectrometry and by partial synthesis from chlorophyll a. The pigment is isolated from Spirulina geitleri irrespective of the use or omission of chlorinated substances during the isolation procedure.

Chromatography : basic principles, sample preparations and related methods

Abstract: General Concepts Gas chromatography (GC) High Performance Liquid Chromatography (HPLC) Thin Layer Chromatography (TLC) Supercritical Fluid Chromatography (SFC) Electrophoresis and Potential Driven Chromatography Chromatography on a Chip Field-Flow fractionation (FFF) Sample preparation Quantitation

Conjoint radioenzymatic measurement of catecholamines, their catechol metabolites and DOPA in biological samples.

Abstract: An assay is described for the simultaneous determination of dopamine, noradrenaline, adrenaline, dopa, 3,4-dihydroxyphenylacetic acid, 3,4-dihydroxyphenyl-ethanol, 3,4-dihydroxymandelic acid and 3,4-dihydroxy-phenylglycol, capable of detecting amounts in the femtomol range The assay is based on the O-methylation of the catechol moiety utilizing S-[3H-methyl]-adenosyl-l-methionine and a partially purified catechol-O-methyl transferase to form the various O-[3H-methyl]-catechol derivatives The O-[3H-methyl]-catechol derivatives are purified by thin layer chromatography, solvent partitions and/or ion exchange chromatography The assay was successfully applied to biological sample It was possible for the first time, to detect free 3,4-dihydroxy-phenylglycol, free 3,4-dihydroxyphenylethanol and 3,4-dihydroxymandelic acid in a small volume (25μl) of blood plasma of man, rat, dog and rabbit The conjoint measurement of catecholamines and their catechol metabolites in minute amounts of biological samples may contribute to a more detailed understanding of catecholamine metabolism in the peripheral and central nervous system

Trichothecenes and their analysis

Abstract: The analysis of foods and feeds for the naturally occurringFusarium produced trichothecenes is reviewed. Each major step (extraction, purification and detection-quantitation) is discussed. Although none of the extraction solvents has been thoroughly evaluated, aqueous metanol is the preferred system in most of the published procedures. The sample extracts are generally purified by liquid-liquid partitions followed by silica gel column and/or preparative thin layer chromatography (TLC). Both thin layer and gas liquid chromatography (GLC) are used for the detection and quantitation of the trichothecenes. The detection limit for the GLC procedures has not been determined in most of the reported methods; however, T-2 toxin, diacetoxyscirpenol, deoxynivalenol, and neosolaniol have been detected in the 25–100 ng/g range.