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  • Electronic Resource  (4)
  • 1975-1979  (3)
  • 1965-1969  (1)
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  • Electronic Resource  (4)
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  • 1
    ISSN: 1612-1112
    Keywords: Glass capilary GC ; Heat resistant surface deactivation ; Testmixtures ; Polycyclic aromatic hydrocarbons
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A new method of making alkylpolysiloxane (OV 1, OV 101, OV 17, Dexsil 400, SE 52, SE 54) columns with high stability at temperatures above 300°C of both the stationary liquid itself (low bleeding) and of the surface deactivation (no tailing of polar solutes with extended use at temperatures beyond 250°C) is described. The best results were achieved on dealkalinized alkali glass but also on borosilicate surfaces which have been additionally HF treated before coating in both cases. The procedure can also be applied to leached alkali and borosilicate surfaces successfully. The best deactivations of the glass surface are attained in a two step procedure: firstly by treatment with gaseous HF/N2 mixture and secondly by simple heating of the coated and closed column at temperatures between 350° and 450°C for several hours. The tailing behaviour of such columns for polar solutes is considerably improved by this procedure as shown by test chromatograms. The procedure can also be applied to leached alkali and borosilicate surfaces successfully.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 10 (1977), S. 580-587 
    ISSN: 1612-1112
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary An introductory discussion is given on the manufacture of glass capillary columns, including details of the methods of column testing and of the properties of the inner surfaces of glass capillaries. As a result a simple method for the testing of various kinds of support surfaces is presented which allows stepwise control of the column making procedure. A new kind of pretreatment of soft glass surfaces with HCl and HF at 450°C is described which allows the production of non-polar columns with much improved tailing behaviour for strongly polar solutes. Concerning capillary column sampling a new technique of “direct” sampling without previous vaporisation of the sample outside the column is presented together with a double column system for “selective” sampling of complex mixtures.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 2 (1969), S. 11-13 
    ISSN: 1612-1112
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Es wird eine Vorrichtung zum Anschluß von Glaskapillaren beschrieben, bei der die Verbindung der Glaskapillaren mit den Metallteilen nicht gelöst werden muß, wenn die Säule ausgewechselt werden soll. Die Geometrie der Kapillare auf dem Säulenkörper ist nicht bruchempfindlich und durch geringfügiges Verbiegen der Enden in einer kleinen Gasflamme herzustellen. Wichtig ist die richtige Führung der Ströme des Trägergases im Splitteil und des Spülgases im Beschleunigerteil, die etwaige Totvolumina nicht zur Auswirkung auf die Trennleistung gelangen läßt. Split-und Beschleunigungsteil wurden dazu auf den Säulenkörper verlegt. Zum Säulenwechsel werden nur Verbindungen zum Gerät gelöst, die von großen Gasströmen durchflossen werden.
    Abstract: Sommaire On décrit un système pour la connexion de capillaires en verre dans des appareils de chromatographie en phase gazeuse commerciaux, où la connexion entre capillaire en verre partie métallique ne doit pas être défaite si la colonne est changée. La forme simple et donc non fragile du capillaire en verre de ce système s'obtient facilement par courbure au moyen d'une petite flamme de gaz. Il est important pour la construction de ce système d'amener les flux du gaz vecteur au point de partage et le gaz de balayage au bout de la colonne, de sorte que des volumes morts dus aux connexions n'influencent pas le pouvoir de séparation du système. Les pièces d'introduction du gaz de balayage et de partage sont incorporées au dispositif mentionné. Pour changer de colonnes, il faut détacher seulement les connexions où passent des débits gazeux élevés.
    Notes: Summary A device for the connection of glass capillaries within commercial gas chromatographs is described in which the fitting between the glass capillary and the metal parts does not have to be loosened to change the column. The simple and robust geometry of the glass capillary in this device is easily obtained by bending in a small gas flame. It is important in the construction of the device to avoid dead volumes in the connections to the sample split, the scavenge gas and at the column end, that might impair the separation efficiency of the system. The scavenge gas introduction and split parts are included in the device. For column change only joints which have high gas rates through them are loosened.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 8 (1975), S. 517-530 
    ISSN: 1612-1112
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary After a general introduction on the advantages and special requirements of gas chromatography in glass capillaries the methods of preparing and testing thin film capillaries are described to an extent not convered in the authors' previous paper. By means of a series of chromatograms of typical artificial and genuine samples it is shown that the use of glass capillaries of variable length and with various stationary liquids does not present technical or methodical difficulties. With regard to temperature stability there is no difference in performance between packed and glass capillary columns. Moreover the preparation of glass capillary columns is easy, their separation efficiency is much better and the tailing behaviour is often superior in comparison with packed columns.
    Type of Medium: Electronic Resource
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