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.

Smart thin layer chromatography plate.

Abstract: We present an innovative thin layer chromatography plate, which integrates a linear array of amorphous silicon photodiodes for real-time qualitative and quantitative chromatographic analysis.

Thin-layer chromatography of pteroylmonoglutamates and related compounds.

Abstract: Publisher Summary This chapter discusses thin-layer chromatography (TLC) of pteroylmonoglutamates and related compounds. The naturally occurring pteroylmonoglutamates can be separated from each other and identified by TLC. A single solvent system— namely, 3.0% (w/v) NH 4 Cl— gives good separation of most of the more important derivatives. The separated folates can be detected on the TLC plates, either by their fluorescent properties or, if they are present in trace amounts, by the removal of the powder in sections from the plates followed by desorption and microbiological assay, using Lactobacillus casei . This technique is not suitable for the separation of folate polyglutamates, and where these forms exist, they must be converted to the corresponding folate monoglutamate by enzymic hydrolysis prior to their separation. The pteroylmonoglutamate standards containing 0.5% MET are applied in the minimum possible volume so that approximately 5 μg of each derivative are applied. Biological extracts are also applied in minimum volume to achieve a concentration greater than 50 μg of folate activity per sample. Where the levels of folates are low, thicker plates may be used and more sample applied or the sample may be lyophilized and resuspended prior to the application. The plates are developed in different solvents at room temperature, usually for 80-90 min.

Metabolic Fate of Aromatic Hydrocarbons in Aquatic Organisms: Analysis of Metabolites by Thin-Layer Chromatography and High-Pressure Liquid Chromatography

Abstract: Aquatic organisms convert aromatic hydrocarbons into a variety of conjugated and nonconjugated derivatives. Analytical techniques based on thin-layer chromatography (TLC) and high-pressure liquid chromatography (HPLC) were employed to separate, identify and quantitate individual metabolites from fish exposed to radiolabeled naphthalene and 2,6-dimethylnaphthalene. Significant differences in profiles of individual metabolites were found in relation to the type of biological sample analyzed. Liver of naphthalene-exposed salmonids contained eight polar derivatives, as shown by HPLC. Two nonconjugates (1-naphthol and 1,2-dihydro-1,2-dihydroxynaphthalene) and three conjugates (1-naphthyl glucuronic acid, 1-naphthyl sulfate and 1-naphthyl glucoside) were identified. HPLC revealed that brain of 3H-naphthalene-exposed trout contained essentially the nonconjugated derivatives, 1-naphthol and 1,2-dihydro-1,2-dihydroxynaphthalene. TLC showed that the metabolites from trout urine were 1-naphthol, 1,2-dihydro-1,2-dihydroxynapthalene, and 1-naphthyl glucuronic acid (99% of the total metabolites detected). Major components of the metabolite fractions of tissues and biological fluids were 1,2-dihydro-1,2-dihydroxy and glucuronic acid derivatives. Dihydrodiol derivatives arise from the corresponding arene oxides, some of which have been shown to be cytotoxic to certain mammalian systems.

Combination of thin layer chromatography and gas chromatography in the analysis on a microgram scale of lipids from wheat flour and wheat flour doughs.

Abstract: Lipids were extacted on a microgram scale from 3 to 6 mg flour or from freeze-dried dough by percolation. The impure extract was separated into 12 nonpolar and 14 polar lipids by TLC. Then the fatty acid composition of most of these lipids was determined by gas chromatography. The microscale method renders possible qualitative and quantitative determination of the composition of the lipids in minute quantities of flour and dough. The selectivity of different extraction solvents was studied. In both flour and dough the fatty acid composition of a given component is identical in the free and bound lipid fractions. In dough, the quantity of free lipids is less than in flour; the extent of the decrease depends on the atmosphere in which it is mixed. During mixing, the carotenoid pigments, α-monoglycerides and the free linoleic acid and linolenic acid are oxidized. Oxidation is apparently a function of the concentration of oxygen and of lipoxidase.