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  • Analytical Chemistry and Spectroscopy  (3)
  • Analyse von Polycyclen, aromat. aus Luftstaubextrakten  (1)
  • 1
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 4 (1981), S. 209-214 
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Capillary, fused silica ; Capillary GC/MS ; PAH, M.W. 300-402 ; Airborne particulate matter ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Gas chromatography (GC), low-voltage mass spectrometry (LV MS), and gas chromatography/mass spectrometry (GC/MS) have been used for detecting polycyclic aromatic hydrocarbons (PAH) of molecular weight between 300 and 402 in airborne particulate matter. Nearly 200 high molecular PAH separated by fused silica capillary columns could be characterized by their El mass spectra. The lack of reference substances precluded further structure elucidation.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1618-2650
    Keywords: Analyse von Polycyclen, aromat. aus Luftstaubextrakten ; Chromatographie, Gas, Capillar ; Best. von Störsubstanzen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Ein vielfach angewandtes capillargas-chromatographisches Verfahren zur Bestimmung von polycyclischen aromatischen Kohlenwasserstoffen (PAH) in der Atmosphäre wurde auf seine Zuverlässigkeit bei der Gewinnung von quantitativen Analysendaten hin geprüft. Eine PAH-Fraktion, die in unserem Labor routinemäßig durch Extraktion von atmosphärischem Schwebstaub mit Methanol, Flüssig-Flüssig-Verteilung (Cyclohexan/Methanol-Wasser) und zwei säulenchromatographischen Trennungen (SiO2/Cyclohexan und Sephadex LH-20/Propanol-2) gewonnen wird, wurde bei dem letzten chromatographischen Schritt (Sephadex LH-20/Propanol-2) weiter fraktioniert. Durch Untersuchung der so erhaltenen Fraktionen mit Hilfe der Capillar-Gas-Chromatographie und der GC-MS-Kopplung wurden für 14 ausgewählte PAH Überlagerungen durch Störsubstanzen qualitativ und quantitativ ermittelt. Dabei zeigte sich, daß ein Teil der Fehler vermieden werden kann, wenn die PAH mit zwei und drei Ringen exakt von den interessierenden PAH mit vier und mehr Ringen abgetrennt werden. Für einige PAH sind die quantitativen Ergebnisse jedoch auch bei richtiger Schnittpunktwahl mit Vorsicht zu bewerten; zu diesen Verbindungen gehört auch das oftmals als Maß für die cancerogene Potenz einer PAH-Fraktion angesehene Benzo(a)pyren.
    Notes: Summary Glass capillary gas chromatography was checked with regard to the authenticity of quantitative results for the analysis of polycyclic aromatic hydrocarbons (PAHs) in airborne particulate matter. A PAH fraction, which was routinely separated from particulate matter by solvent extraction (methanol), liquid-liquid partition (cyclohexane/methanol-water) and two steps of column chromatography (SiO2/cyclohexane and Sephadex LH-20/propanol-2), was further fractionated with the above mentioned Chromatographic system Sephadex LH-20/propanol-2. By analyzing the fractions obtained so far with glass capillary chromatography and g.c.-m.s. coupling, the interfering substances were determined qualitatively and quantitatively concerning 14 selected PAHs. It was shown that some errors in determining PAH values may be avoided, if PAHs with less than four rings are exactly separated from those with four and more rings in the last Chromatographic step; but quantitative data for some PAHs may be biased even in case of a well separated PAH fraction. One of these PAHs is the well known benzo(a)pyrene, which has often been considered as an indicator for the carcinogenic potency of the PAHs in general.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Journal of Raman Spectroscopy 8 (1979), S. 244-248 
    ISSN: 0377-0486
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The influence of the chain conformation on the ν1 and ν13 normal modes of the benzene ring in atactic and isotactic polystyrene and their model compounds has been investigated by Raman spectroscopy. The ν1 mode which appears in the 750-800 cm-1 region is influenced as much by the local conformation of the alkyl chain as by the length of the considered conformational structure along the chain. The ν13 mode which appears in the 1195-1215 cm-1 region is only influenced by the local conformation and is insensitive to the length of the alkyl chain.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Journal of Raman Spectroscopy 5 (1976), S. 417-428 
    ISSN: 0377-0486
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The Raman spectra of predominantly trans - 1,4-polychloroprenes are presented. Spectra were recorded of polymers prepared by free radical emulsion techniques in the temperature range -20 to +40°C in both the solid state and in CS2 solution. Spectral changes characteristic of the crystalline and amorphous regions of the polymers have been identified. Measurements of the relative broadness of the 1007 cm-1 Raman line, which is associated with the C-C stretching frequency in the main chain, have been made and correlated with the amorphous content of the polymer. Extrapolations of these results indicates that polymers prepared in the range 50-60°C should be completely amorphous elastomeric materials.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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