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  • 1
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    Contact dermatitis 19 (1988), S. 0 
    ISSN: 1600-0536
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Irritancy of daffodil flowers and bulbs was assessed using various fresh plant preparations, solvent extracts and some of the known Amaryllidaceae alkaloids on guinea pigs. Sensitization was also carried out on guinea pigs using these plant preparations. solvent extracts and 7 fractions obtained after preparative chromatography of the bulb ether extract. Only 1 fraction, containing 2 alkaloids, was capable of inducing delayed hypersensitivity in the animals: the sensitivity achieved, however, was weak. The substances were identified as masonin and homolycorin, which acted as elicitors. but masonin may also be a sensitizer. While homolycorin is a known daffodil constituent, masonin has not been found previously in Narcissus pseudonarcissus. 3 other alkaloids as well as chelidonic acid and isorhamnetin were non-elicitors in the sensitized guinea pigs.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 2
    Digitale Medien
    Digitale Medien
    Springer
    Chromatographia 48 (1998), S. 127-132 
    ISSN: 1612-1112
    Schlagwort(e): Gas chromatography-mass spectrometry ; Solid-phase microextraction ; Headspace analysis ; Unsaturated aldehydes
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary A fast and simple headspace SPME sampling method has been developed for quantification of volatile aliphatic aldehydes in sunflower oil. Analysis has been performed by gas chromatography, on a 30m×0.25 mm i.d. ×0.25 μm CP-Wax 52CB column, with mass spectrometric detection. Carryover from the SPME fiber could be eliminated by heating the fiber in the injection port between runs. Response factors of all the compounds were linear for concentrations up to 100 ng μL−1. The slopes of the calibration curves decrease with the amount of saturation of the aldehydes. The average responses for unsaturated aldehydes were twice as high as those for the saturated variety. Responses for dienes were approximately one order of magnitude higher than for saturated aldehydes. Depletion of the analyte was examined by repeated extraction from the same vial. SPME was optimized—after 30 min extraction most components were found to have reached equilibration. The detection limit for the compounds studied varied between 0.1 and 1 ng μL−1. Distribution constants were determined for ten different aldehydes and Henry's constants were calculated for unsaturated aldehydes. There was a definite relationship between the response factors and the amount of saturation of the aldehydes.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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