Improved separation of amino acids by thin-layer chromatography

Summary The separation of 35 amino acids on Avicel F layers was investigated and 6 solvent systems are recommended for use either singly or in combination in 2-dimensional chromatography. The mechanisms and limitations of these methods are discussed.     

Identification of twenty amino acids by circular thin-layer chromatography

Summary A method has been developed for the separation and identification of 20 common amino acids by circular thin-layer chromatography. The amino acids are separated to neutral, acid, and basic groups by electrolysis and then identified by circular TLC. The method is simple and development of a chromatoplate is complete in about 3 minutes. The application of the method is illustrated by the analysis of amino acids in foods and in urine.

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Zusammenfassung Zur Trennung und Identifizierung 20 gewöhnlicher Aminosäuren wurde ein chromatographisches Verfahren entwickelt. Die Aminosäuren werden elektrolytisch in neutrale, basische und saure getrennt und dann auf kreisförmiger Dünnschichte chromatographiert. Die Entwicklung des Chromatogramms ist in 3 Minuten beendet. Die Anwendung zur Analyse von Lebensmitteln und Harn wird beschrieben.

     

Screening for amino acid disorders by thin-layer chromatography of the dansyl amino acids

Summary A procedure is described for the screening of disorders of amino acid metabolism or tranpsort. The amino acids and other reactive constituents present in a small volume of deproteinized plasma or urine are derivatized with dansyl chloride. Desalting or concentrating of urine is not required. The fluorescent derivatives are separated by two-dimensional thin-layer chromatography and visualized by ultraviolet radiation. The time of development is less than 1 hr. The derivatives of thirty-seven amino acids and related constituents found in physiological fluids have been mapped in the system. A standard, reflective of normal plasma, is used to aid in identification of those derivatives generally observed on plasma and urine chromatograms and in detection of aminoacidemias. Aminoacidurias are detected by observing derivatives that in relation to others are present in greater than normal amounts.

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Analytischer Nachweis von Störungen des Aminosäurestoffwechsels durch Dünnschicht-Chromatographie der Dansylverbindungen

Zusammenfassung Dansylderivate von Aminosäuren und anderen reaktionsfähigen Stoffen in kleinen Volumina enteiweißten Plasmas oder Harns wurden hergestellt. Entsalzung oder Einengung des Harns ist nicht notwendig. Die fluoreszierenden Derivate werden durch zweidimensionale Dünnschichtchromatographie getrennt und im UV nachgewiesen. Die dazu erforderliche Zeit ist kürzer als 1 Stunde. Die Derivate von 37 Aminosäuren und verwandten Verbindungen in physiologischen Flüssigkeiten wurden erfaßt. In üblicherweise zur Beobachtung gelangenden Plasma- bzw. Harnchromatogrammen feststellbare Aminosäuren dienen zum Vergleich mit abnormalen Ergebnissen.

     

Application of iodine-azide reaction for detection of amino acids in thin-layer chromatography

The iodine-azide reaction was employed to TLC detection of sulphur-containing derivatives of protein and some non-protein amino acids. The derivatization reaction with phenyl isothiocyanate (PITC) took place directly on the plate before the developing step. Subsequently, the plates were sprayed with a mixture of sodium azide and starch solution in NP-TLC and in the case of RP-TLC sodium azide solution with starch incorporated into mobile phase and then exposed to iodine vapour. The spots became visible as white spots on violet-grey background. The obtained detection limits of PTC-derivatives have been compared with other visualizing techniques commonly used in TLC practice (UV254 and iodine vapour). The iodine-azide system has been proved to be the most favourable and enabled to detect quantities per spot in the range of 1-60 pmol (HPTLC) and 3-100 pmol (TLC).