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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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Book ChapterDOI
TL;DR: This chapter discusses the principal, materials, reagents, and procedures of thin-layer chromatography of citric acid cycle intermediates and some related amino acids, which is adopted successfully in metabolic studies.
Abstract: Publisher Summary This chapter discusses the principal, materials, reagents, and procedures of thin-layer chromatography. The citric acid cycle intermediates and some related amino acids are separated by two-dimensional cellulose thin-layer chromatography. After separation, the compounds are visualized by spraying with an acid-base indicator or ninhydrin. As the compounds studied are normally present in only trace amounts in most biological extracts, it is often necessary to use substrates labeled with isotopes. In these cases, the spots are identified with the help of mixtures of unlabeled known compounds. Techniques for the radioassay of the plates are well developed. This chromatographic technique, including the usage of compounds labeled with 14 C, is adopted successfully in metabolic studies. For detection of the carboxylic acids, the plates are sprayed with bromcresol green indicator. The separation of the eight intermediates of the citric acid cycle is good with the exception of the citratc-isocitrate spots. Biological samples may be deproteinized prior to chromatography by trichloroacetic acid or perchloric acid. The former may be removed by evaporation and the latter removed by adding an equivalent amount of KOH or KHCO 3 .

33 citations

Journal ArticleDOI
TL;DR: This thin-layer chromatography method should prove useful for the routine screening of shellfish tissues in those laboratories not equipped with an LC system and should also be useful as a chemical confirmation method for DA in samples tested positive by assay methods such as immunoassay.
Abstract: A thin-layer chromatography (TLC) method has been developed for the semi-quantitative analysis of domoic acid (DA) in shellfish tissues. Tissues were extracted in a single-step homogenization of tissue with 50 % aqueous methanol and then taken through a selective strong anion exchange cleanup. Cleaned extracts were applied directly to silica gel TLC plates and developed with a butanol–acetic acid–water mixture (3:1:1, Rf = 0.45 for DA). As little as 10 µg DA per gram of tissue could be detected after chromatography using a hand-held short-wave UV lamp to detect fluorescence quenching. Confirmation was provided by spraying the plate with ninhydrin, which reacts with the secondary amine of DA to give a distinctive yellow colored product. The extraction, cleanup and TLC procedures are fast and simple, and do not require the use of expensive equipment. This method should prove useful for the routine screening of shellfish tissues in those laboratories not equipped with an LC system. It should also be useful as a chemical confirmation method for DA in samples tested positive by assay methods such as immunoassay. Copyright © 1999 John Wiley & Sons, Ltd.

33 citations

Journal ArticleDOI
TL;DR: In this paper, the content of total phenolic compounds, determined by UV spectrophotometric method using the Folin-Ciocalteu reagent, was 15.12 mg/g.
Abstract: The methanol, petroleum ether, chloroform, ethyl acetate, n-butanol and water extracts were obtained by extraction of marigold flower (Calendula officinalis L.). The content of total phenolic compounds, determined by UV spectrophotometric method using the Folin-Ciocalteu reagent, was 15.12 mg/g. The content of total flavonoids, determined by UV spectrophotometric method according to Markham, was 5.13 mg/g. Qualitative determination of phenolic compounds in the extracts was performed by one- and two-dimensional thin-layer chromatography (TLC) procedures. The results of one- and two-dimensional TLC analyses showed that different flavonoids and phenolic acids were present in the investigated extracts. The greatest number of flavonoids (rutin, quercetin and some unidentified flavonoid glycosides) and phenolic acids (chlorogenic, caffeic, coumaric and vanillic acid) were deteminated in methanol extract. The influence of marigold extracts, in concentration range 0.6-1.2 mg/mL, on 2,2’diphenyl-1-picrylhydrazyl (DPPH) free radicals was investigated by electron spin resonance (ESR) spectroscopy. All extracts showed scavenging activity (SA) in the following order: ethyl acetate > n-butanol > methanol > water > chloroform > petroleum ether. The SA increased with increasing concentration of extracts. The ethyl acetate and nbutanol extracts exibited the most significant SA. These extracts in concentration of 1.2 mg/mL eliminated completely DPPH radicals. The lowest SA had chloroform and petroleum ether extracts (in concentration of 0.6 mg/mL SA=0%). The SA of marigold extracts is attributed to its hydrogen-donating ability and scavenging effect.

33 citations

Journal ArticleDOI
TL;DR: The techniques allow a rapid determination of the redox state of quinones in biological materials and the relative R f values of synthetic and naturally occurring quinone, chromanols, and hydroquinones on silica gel G in various solvent systems are given.

33 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202388
2022209
202159
202068
201990
201881