scispace - formally typeset
Search or ask a question

Showing papers on "Thin-layer chromatography published in 1972"




Journal ArticleDOI
TL;DR: The combination of a thin-layer chromatographic system, which makes the previous separation of glycolipids by column chromatography unnecessary, with the orcinol reaction carried out in the presence of silica gel permitted a rapid and simple determination of cerebrosides, sulphatides and monogalactosyl diglyceride with as little as 50 mg of brain tissue.

67 citations


Journal ArticleDOI
01 May 1972-Steroids
TL;DR: A specific, sensitive and reliable radioligand assay for plasma dehydroepiandrosterone (DHA) and its sulfate has been developed and was successfully separated from cross-reacting Δ 5 -steroids by thin layer chromatography.

50 citations


Journal ArticleDOI
TL;DR: Methods for separation and analysis of products using only thin-layer chromatography on polyethylenimine-cellulose have been developed and a single-site break between nucleotides 61 and 62 is revealed.

46 citations


Journal ArticleDOI
TL;DR: Changes in the fatty acid composition of egg-yolk fat of hens fed diets with increasing fish meal content are studied by total fatty acid analysis and show a fatty acid pattern similar to those of the diets themselves.
Abstract: Changes in the fatty acid composition of egg-yolk fat of hens fed diets with increasing fish meal content are studied by total fatty acid analysis. The fatty acid composition of the major lipid fractions in egg-yolk fat after feeding a high-level fish meal diet was determined by a combination of thin layer chromatography (t.l.c.) and gas-liquid chromatography (g.l.c.) The changes produced show a fatty acid pattern similar to those of the diets themselves. Long-chain polyunsaturated fatty acids are deposited preferentially in the phospholipids, reaching the highest concentration in cephalin and lecithin.

42 citations





Book ChapterDOI
01 Jan 1972
TL;DR: In this paper, the authors focus on thin-layer chromatography (TLC) for the quantitative determination of carbohydrates, which is used for the determination of the kinetics, mechanism, or percentage of products of a carbohydrate reaction but is limited to the components that can be completely separated.
Abstract: Publisher Summary This chapter focuses on the thin-layer chromatography (TLC). TLC is increasingly being used for the quantitative determination of carbohydrates. The procedure is excellent for the determination of the kinetics, mechanism, or percentage of products of a carbohydrate reaction but is limited to the components that can be completely separated. There are several methods available that can be separated into two major groups: (1) direct quantitative determination—estimation of the compound directly on the plate and (2) indirect quantitative determination—elution of the compound from the plate followed by some physical estimation. In some of the methods, destruction of the carbohydrate is not necessary, and the compounds can then be used for further qualitative analysis by means of infrared radiation (IR), nuclear magnetic resonance (NMR), and ultraviolet (UV) spectroscopy.

27 citations


Journal ArticleDOI
TL;DR: Methods utilized in the laboratory for the rapid toxicological analysis of emergency room patient urine samples include Amberlite XAD-2 resin column Chromatographic separation from biologic material, followed by thin-layer chromatography and chromogenic spraying for detection.

Journal ArticleDOI
01 Jan 1972-Analyst
TL;DR: A rapid and accurate method is described for the determination of diosgenin in Dioscorea composita roots by thin-layer chromatography and gas-liquid chromatography to evaluate statistically the accuracy of the method.
Abstract: A rapid and accurate method is described for the determination of diosgenin in Dioscorea composita roots. After acid hydrolysis and solvent extraction of the root, pure diosgenin is isolated by thin-layer chromatography, treated with sulphuric acid-methanol, and the resultant chromophore is measured by spectrophotometry.Similarly, gas-liquid chromatography is used to evaluate statistically the accuracy of the method.





Journal ArticleDOI
TL;DR: In this paper, the authors showed that the method of RF corrections originally proposed by Galanosand Kapoulas for paper chromatography is also applicable to thin-layer chromatography.

Journal ArticleDOI
01 Dec 1972-Lipids
TL;DR: In this paper, saturated monoacid triglycerides were pyrolyzed in a flowing atmosphere of helium at 630-650 C, and the products were colleted at low temperature.
Abstract: Saturated monoacid triglycerides were pyrolyzed in a flowing atmosphere of helium at 630–650 C, and the products were colleted at low temperature. They were fractionated by thin layer chromatography, according to polarity, and were further resolved and analyzed by gas chromatography, mass spectrometry and IR spectrometry. Alkanes, alkenes, ketones, esters, free acids and cyclic products were identified. Among the latter are probably lactones and substituted dioxanes and dioxolanes, for which structures have been postulated. The parent acid of the triglyceride and the cyclic residual products, after loss of one acid group from the triglyceride, were prominent products. Many products of pyrolysis had structures similar to the major ions produced in the mass spectrum of the triglyceride.

Journal ArticleDOI
TL;DR: In this paper, an analytical procedure for studies on the composition of hydrogenated oils containing C20 and C22 fatty acids is presented, which involves an initial separation of esters by preparative gas liquid chromatography into fractions of equal chain length.
Abstract: An analytical procedure is presented for studies on the composition of hydrogenated oils containing C20 and C22 fatty acids The method involves an initial separation of esters by preparative gas liquid chromatography into fractions of equal chain length Each fraction is subsequently studied in detail by gas liquid chromatography, argentation thin layer chromatography, IR spectroscopy, and microozonolysis Results are presented from a study of the isomers of major monoenoic acids in commercial samples of rapeseed and partially hydrogenated rapeseed oils

Journal ArticleDOI
TL;DR: 7-Chloro-4-nitrobenzo-2-oxa -1,3-diazole reacts with primary and secondary amines to produce highly fluorescent compounds, and thin-layer chromatography can be useful to identify qualitatively the drugs involved.
Abstract: 7-Chloro-4-nitrobenzo-2-oxa -1,3-diazole reacts with primary and secondary amines to produce highly fluorescent compounds. The resulting emission spectra for primary and secondary amines are similar; however, when the excitation spectra of these compounds are determined when the emission wavelength is kept at 520 nm, distinctly different results are obtained. Thin-layer chromatography of suitably concentrated aliquots of these solutions yield characteristic spots, the Rf values of which can be used to help identify the substances involved. This reaction was applied to the quantitative determination of amphetamine in biological extracts. If amphetamine is the only drug present it can be quantitated by fluorometry and confirmed by the thin-layer chromatographic procedure. If more than one drug is present, the fluorometric procedure is unsatisfactory for quantitative analysis. Thin-layer chromatography can be useful to identify qualitatively the drugs involved. Gas chromatography is the procedure of choice in these situations.

Journal ArticleDOI
T. Mezzetti1, M. Ghebregziabhier1, S. Rufini1, G. Ciuffini1, M. Lato1 
TL;DR: A new technique, which the authors call “coupled-layer chromatography,” exploits two different chromatographic principles on the same chromatoplate for the separation of a class of substances.

Journal ArticleDOI
Nakao Ariga1
TL;DR: Thin-layer chromatography of keto acid 2,4-dinitrophenylhydrazones was carried out on plate coated with silica gel and sodium bicarbonate and results indicate usefulness of the present method for separation, detection, and determination ofketo acids.


Journal ArticleDOI
TL;DR: The most predominant species of lamb liver phosphatidylinositol is the monoenoic followed by the tetraenoic (17%).
Abstract: 1. Two methods for the fractionation of phosphatidylinositol into molecular species were developed. In addition to preserving the fatty acid moiety of the molecule, the first method preserves the phosphorus, and the second preserves both the phosphorus and inositol ring. 2. In the first method, phosphatidylinositol was oxidized with periodate and the products reacted with diazomethane. I.r. examination showed that the main product was identical with dimethylphosphatidic acid. Fractionation to molecular species was carried out on thin layers impregnated with silver nitrate. The fatty acid composition of the species was determined by gas-liquid chromatography, and their distribution in lamb liver phosphatidylinositol was studied by a method using [(3)H]methanol. 3. In the second method, phosphatidylinositol was acetylated under mild reaction conditions. The major product was the triacetylated derivative of this phospholipid. This was reacted with diazomethane and the methylated-triacetylated phosphatidylinositol was fractionated into molecular species on silver nitrate-impregnated thin layers. Solvent mixtures containing acetone and distilled chloroform were found most suitable for this purpose. The fatty acid composition of the molecular species was determined by g.l.c., and their distribution in lamb liver phosphatidylinositol was studied by a method using [1-(14)C]acetic anhydride during the acetylation reaction. 4. Results from both methods agree fairly well. The most predominant species of lamb liver phosphatidylinositol is the monoenoic (60%) followed by the tetraenoic (17%). The di- and tri-enoic species existed as minor components.



Journal ArticleDOI
TL;DR: The characterization of microgram quantities of a number of naturally occurring and synthetic indoles through a combination of thin-layer chromatography and in situ fluorescence spectroscopy is reported and should find application in the determination of indoles in biological samples.

Journal ArticleDOI
TL;DR: Purification by anion-exchange resin of a rat liver trichloroacetic acid extract permitted the separation of twenty-two compounds by two-dimensional anion -exchange thin-layer chromatography for nucleotides, which proved usefulness for nucleotide identification of small amounts of tissue extracts.