Separation of fat-soluble vitamins by thin-layer chromatography

Summary This paper is dealing with the evaluation of the method for qualitative analyses of fat soluble vitamins by thin-layer chromatography on impregnated starch, cellulose and talc thin layers. Impregnation was carried out with paraffin oil. Complete analyses could be obtained on two plates with two different solvents. Vitamins K₃, K₄ and K₅ were separated with solvent I (water-dioxane-acetone-formaldehyde (85∶20∶15∶25)) whereas the other remain on the start position. Vitamins A-acetate, A-palmitate, K₁, DL-alpha-tocopherol, DL-alpha-tocopherol-acetate, D₂, D₃ were separated with solvent II (acetone-concentrated acetic acid (30∶20)) while K₃, K₄ and K₅ migrate with front. Quick and simple procedures for the preparation of the plates with an impregnated thin layer is given.     

Separation of aliphatic and aromatic amines by thin-layer chromatography using silica gel plates

Summary 28 different aromatic and aliphatic amines have been separated by TLC; 20 solvent systems were examined.     

Identification of seventeen vitamins by circular thin-layer chromatography

Summary A method is described for separation and identification of 17 vitamins by circular-thin layer chromatography. The method is simple and convenient; separation is complete within 2 minutes. The method is very sensitive and is specially suitable for routine identification when quick results are required.

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Zusammenfassung Ein einfaches Verfahren zur Trennung und Identifizierung von 17 Vitaminen durch Dünnschicht-Ring-Chromatographie wird angegeben. Innerhalb von 2 Minuten ist die Trennung vollzogen. Die Methode ist sehr empfindlich und für Routinezwecke besonders geeignet, wenn die Ergebnisse rasch benötigt werden.

     

Separation of phospholipids using a diethylaminoethyl-silica gel column and thin-layer chromatography

Phospholipids derived from egg yolk are readily separated by DEAE-silica gel column chromatography using stepwise gradient elution. The overall recovery of phospholipids from the column is 85-95% at a loading capacity of 120 mg of lipids per 10 g of DEAE-silica gel. The complete separation of eight phospholipids (phosphatidylcholine, sphingomyelin, lysophosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol, phosphatidylserine and lysophosphatidylserine; 5 micrograms each) is also achieved by one-dimensional DEAE-silica gel thin-layer chromatography with the solvent system chloroform-methanol-water-pyridine-58% ammonia solution (130:55:8:4:4, v/v).     

Separation of zirconium by thin-layer chromatography

The thin-layer Chromatographie separation of a number of metal ions [Sc, Y, Zr, La, Sm, Th, U(VI), etc.] with solvent mixtures of mesityl oxide, ethanol and 5M nitric acid on silica gel-cellulose (5:1) thin-layer plates is reported. Zirconium remains stationary whilst the other metal ions move with the solvent, thus allowing a selective separation of zirconium from about 20 metal ions in ratios ranging from 100:1 to 1:100. Mixtures of various metal ions can also be separated.     

Separation of carbohydrates by thin-layer chromatography

Summary The separation of 13 sugars by means of 8 solvents and one- and two-dimensional chromatography on cellulose and starch layers is described. Good results were obtained on cellulose layers.

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Zusammenfassung Die Trennung 13 verschiedener Zucker mit 8 Lösungsmitteln im Wege der ein- und zweidimensionalen Chromatographie auf Zelluloseund Stärkedünnschichten wurde beschrieben. Zelluloseschichten ergeben gute Resultate.

     

Separation of C19 and C21 dihydroxysteroids by open-hole tubular glass columns and lipophilic gel chromatography.

The combination of lipophilic gel chromatography and high-resolution glass capillary chromatography has been shown to be an important means of identification and quantification of steroid urinary metabolites. Some problems in the use of capillary columns, such as coating with polar and apolar stationary phases, column performance, thermal stability and injection systems have been investigated and this type of chromatography has been used in the analysis of 33 dihydroxysteroids. Gel chromatography is a method complementary to high-efficiency gas chromatography. The steroids are eluted according to the number of hydroxyl groups in the molecules.     

Semiquantitative determination of water-soluble vitamins by circular thin-layer chromatography

Summary A method for semiquantitative determination of water-soluble vitamins such as thiamin hydrochloride, riboflavin, pyridoxine, choline chloride,p-aminobenzoic acid, cyanocobalamine, nicotinic acid and ascorbic acid is described. It involves making circular spots or rings on chromatoplates using circular thin-layer chromatographic apparatus. The method is based on sensitivity and specificity of spot reactions together with comparison of the color intensity of a circular spot with that of sensitivity standard. The accuracy of the method is ± 5%. The usefulness of the procedure has been illustrated by determining the water-soluble vitamins from multi-vitamin tablets and injections.

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Zusammenfassung Eine Methode zur halbquantitativen Bestimmung wasserlöslicher Vitamine wie Thiaminhydrochlorid, Riboflavin, Pyridoxin, Cholinchlorid,p-Aminobenzoesäure, Cyanokobalamin, Nikotinsäure und Ascorbinsäure wurde beschrieben. Sie beruht auf der Herstellung von Kreisflecken oder Ringen im Wege der Dünnschichtchromatographie. Empfindliche und spezifische Reaktionen dienen zum Vergleich der Farbintensität mit Standardlösungen. Die Genauigkeit beträgt etwa ±5%. Das Verfahren wurde an Multivitamintabletten und Injektionslösungen geprüft.