Uranextraktion mit Triphenylarsinoxid

Zusammenfassung Es wird eine neue extraktive Trennungsmethode für Uran beschrieben. Mit Hilfe einer Lösung von Triphenylarsinoxid in Chloroform lassen sich Uranylionen aus wäßriger Lösung im pH-Gebiet von 2 bis 3 extrahieren. Trennungen von verschiedenen anderen Metallionen sind ohne Schwierigkeiten möglich; im Falle von Mitextraktionen kann mit Äthylendiamintetraacetat maskiert werden. Trennungsbeispiele werden angegeben.

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Summary Uranyl ions can be extracted from aqueous solutions by means of triphenylarsinic oxide in chloroform within a pH range of 2 to 3. Separations from several foreign ions can be achieved without any complications; ions co-extracted with uranium can be masked by EDTA. Examples are described.

     

Synthesis and Structures of the Novel Pyridoxal Oxime Derivatives

Novel pyridoxal oxime derivatives were prepared and characterized by means of IR, ¹H and ¹³C NMR spectroscopy. The crystal structures of the 3-hydroxy-4-hydroxyiminomethyl-5-hydroxymethyl-1,2-dimethylpyridinium iodide 1 and 3-hydroxy-4-hydroxyiminomethyl-5-hydroxymethyl-1,2-dimethylpyridinium chloride monohydrate 2 were determined by X-ray analysis. The both compounds crystallize in the triclinic crystal system, space group P . Crystal data: 1 a = 6.286(2) Å, b = 8.748(4) Å, c = 11.736(4) Å, = 104.02(3)°, = 94.70(3)°, = 107.44(6)°, V = 589.0(4) ų, Z = 2, R = 0.0526; 2 a = 6.8980(5) Å, b = 8.6409(6) Å, c = 11.1777(6) Å, = 111.138(5)°, = 93.114(6)°, = 105.158(5)°, V = 591.57(7) ų, Z = 2, R = 0.0492. The bond distances and angles in both structures agree very well. The main difference between these structures was observed in the orientation of the hydroxymethyl group with respect to the pyridinium ring. In the both structures intramolecular hydrogen bond forming six-membered ring were observed. The intermolecular OsI hydrogen bonds in the crystal structure of the compound 1 form dimers. In the crystal structure of compound 2, the water molecules and chlorines build eight-membered rings, which are also connected to pyridinium cations by OsCl and OsO intermolecular hydrogen bonds forming a three-dimensional network.     

Screening for unknown compounds in complex matrices analysed by liquid chromatography: An overview

Rapid scanning UV/visible spectrophotometry, video fluorimetry, mass spectrometry and electrochemical characterization hold great promise for structure elucidation of components of complex mixtures separated by HPLC. As technology continues to improve, newer techniques, such as Fourier transform nuclear magnetic resonance and infrared spectroscopy, are emerging as alternative or complementary methods of detection.