Separation and fluorodensitometric determination of some tropolone alkaloids by thin-layer chromatography

Chromatographia - The tropolone alkaloids colchicine, colchiceine, demecolcine, demecolceine, isocolchicine, isocolchiceine, N-deacetylcolchicine, N-deacetylcolchiceine,...     

Alcohol separation by thin-layer chromatography. II

Summary Thin-layer chromatography on rice starch, maize starch, cellulose and talc makes possible the separation of the homologous series of 3,5-dinitrobenzoates of aliphatic alcohols C₁ to C₂₀. Six different solvent systems have been employed. Dependence of R _f-values on the number of C-atoms on various supports is discussed.Part I: Fresenius Z. Anal. Chem. 264, 415 (1973)     

Semiquantitative determination of alkaloids by circular thin-layer chromatography

Summary A semiquantitative method for the determination of 13 alkaloids (nicotine, quinine, strychnine, brucine, ephedrine, pilocarpine, narcotine, cinchonine, ajmaline, atropine, cocaine, papaverine and morphine) from a single drop of solution by making circular spots on chromatoplate with the circular thin-layer Chromatographic apparatus and their comparison with sensitivity standard has been developed. The accuracy is ±5% and the procedure is rapid, simple and economical.

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Zusammenfassung Ein halbquantitatives Verfahren zur Bestimmung von 13 Alkaloiden (Nikotin, Chinin, Strychnin, Brucin, Ephedrin, Pilokarpin, Narkotin, Cinchonin, Aimalin, Atropin, Kokain, Papaverin und Morphin) in 1 Tropfen Lösung durch zirkuläre Dünnschichtchromatographie und Vergleich mit Standard-Ringen wurde ausgearbeitet. Die Genauigkeit des Verfahrens beträgt ±5%.

     

Application of thin-layer chromatography on purification,separation, and quantitative determination of steroid metabolites

Summary The behaviour of model steroids, 17-ketosteroid formates, acetates, bromides, and dinitrophenylhydrazones, and of extracts obtained from biological material has been studied by means of thin-layer chromatography.Although oestrogens excreted in the urine were readily separable on thin layers, their recovery was unsatisfactory. Thin-layer chromatography has not proved suitable for the separation of the individual urinary 17-ketosteroids. However, it was suitable for the determination of dehydroepiandrosterone and androsterone in peripheral blood. The principle of a method for the determination of individual pregnanetriols has been described. Thin-layer chromatography was well suited for the separation of cortisol, cortisone and aldosterone from urinary aspecific chromogens.

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Zusammenfassung Das Verhalten von Modellsteroiden, 17-Ketosteroidformiaten, -acetaten,-bromiden und -dinitrophenylhydrazonen sowie von Extrakten aus biologischem Material wurde dünnschichtchromatographisch untersucht. Wiewohl mit dem Harn ausgeschiedene Östrogene auf Dünnschichten gut trennbar sind, konnten sie nicht in befriedigender Weise aufgefunden werden. Die Dünnschichtchromatographie eignet sich nicht für die Auftrennung der einzelnen 17-Ketosteroide im Harn, hingegen für die Bestimmung von Dehydroepiandrosteron und Androsteron in peripherem Blut. Das Prinzip einer Bestimmungsmethode für einzelne Pregnantriole wurde beschrieben. Die Dünnschichtchromatographie eignet sich gut zur Trennung von Cortisol, Cortison und Aldosteron von unspezifischen Harnchromogenen.

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Résumé On a étudié par chromatographie en couche mince le comportement de stéroïdes de référence, formiates, acétates, bromures et dinitrophenylhydrazones des cétostéroïdes en C₁₇ et d'extraits obtenus à partir d'une substance biologique.Bien que l'on puisse séparer rapidement sur couche mince les oestrogènes éliminés dans l'urine, leur récupération n'a pas été satisfaisante. La Chromatographie en couche mince ne s'est pas montrée apte à la séparation des cétostéroïdes en C₁₇ sur l'urine individuelle. Elle donne cependant de bons résultats pour le dosage de la déhydro-épiandrostérone et de l'androstérone dans le sang périphérique. On a décrit le principe d'une méthode de dosage des pregnanetriols individuels. La chromatographie en couche mince convient bien pour la séparation du cortisol, de la cortisone et de l'aldostérone des chromogènes urinaires non spécifiques.

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The capable assistance of Mrs.J. S. Haraszti, MissM. Kazik and Mrs.G. S. Karsai is gratefully acknowledged.     

Quantitative determination of the alkaloids ofAnabasis aphylla by thin-layer chromatography

Summary A chromatographic method has been developed for the quantitative determination of the alkaloids ofAnabasis aphylla — anabasine, aphylline, lupinine, aphyllidine, and anabasamine — and also pachycarpine in the mixture of reduction products of the high-boiling fraction of alkaloids, in a thin layer of alumina.V. I. Lenin Tashkent State University. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 772–776, November–December, 1976.     

Detection and determination of N-nitrosamines by thin-layer chromatography using fluorescamine.

A novel procedure is described for the detection and determination of N-nitrosamines (NAs) on thin-layer chromatographic plates. Ultraviolet irradiation of NAs on activated plates (silica gel or aluminum oxide) yields primary or secondary amines, which after spraying with fluorescamine reagent give fluorescent or non-fluorescent products, respectively. The majority of the 24 NAs examined afforded NAs, although the volatile dimethyl-, diethyl- and pyrrolidine-N-nitrosamines gave limits of 500, 40, and 40 ng, respectively. Spectrophotometric determinations of the relative fluorescence of 0.1-40 nmoles of NAs gave rise to nearly linear calibration curves when plotted on a log-log scale.     

Determination of caprolactam by adsorptive voltammetry after separation by thin-layer chromatography

Caprolactam (2-oxohexamethyleneimine) can be determined in wastewaters and natural waters by adsorptive stripping voltammetry after separation of the product of the reaction between caprolactam and p-(N,N-dimethylamino)benzene-p′-azobenzoyl chloride. When a hanging mercury drop electrode is used with an accumulation time of 60 s in stirred solution, caprolactam can be determined from a lower limit of 0.2 μg ml^?1. With a 360-s accumulation time, linear calibration plots are obtained for 8 × 10^?10?8 × 10^?9 mol l^?1 caprolactam. The effect of interfering sample components is eliminated by the TLC separation.