Bibliothek

X
feed icon rss

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
  • 1
    Digitale Medien
    Digitale Medien
    Substituentenabhängigkeit bei der direktentrans →cis-Photoisomerisierung von donator-substituierten 4′-Diphenylphosphinyl-trans-stilbenen (1985)
    Springer
    Monatshefte für Chemie 116 (1985), S. 487-492 
    Details
    ISSN: 1434-4475
    Schlagwort(e): Stilbenes ; trans-cis Photoisomerization ; Influence of substituents
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract From the fluorescence quantum yield ϕ f , the fluorescence decay time τ f w and the quantum yield ϕ tc of thetrans →cis photoisomerization results the fraction α of perpendicular singlet (perp-S1) decaying to ground statetrans-stilbenes1. The α values of the donor substituted 4′-diphenylphosphinyl-trans-stilbenes1 in the solvents toluene andn-propanol are dependent on the donor substituent in1 and the solvent. It is concluded for1 that increasing polarity of the first excited singlet state (tr-S1) promotes thetrans →cis photoisomerization.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00798370
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 2
    Digitale Medien
    Digitale Medien
    A congener-specific method for the quantification of camphechlor (toxaphene) residues in fish and other foodstuffs (1996)
    Springer
    Fresenius' journal of analytical chemistry 354 (1996), S. 81-92 
    Details
    ISSN: 1432-1130
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract. To develop a method for the quantification of camphechlor without the use of complex technical toxaphene as gas-chromatographic standard, all important chlorobornane peaks have been identified in a mixed marine fish sample reflecting the fish consumption in Germany. Further ECD but not ECNI-MS has been found to be suitable for estimation of the relative concentrations of chlorobornanes. The three camphechlor congeners with the highest ECD response have been found in concentrations of 0.05–0.08 mg/kg (fat basis), representing about 50% of the total chlorobornanes present. A predominance of these congeners has also been observed in a standard reference material of cod liver oil (SRM 1588). As these three congeners are presumed to be dominant in human camphechlor intake, it is proposed to use them as indicator components for a congener-specific analysis of camphechlor residues together with a fourth heptachlorobornane which does not accumulate in fish. Cleanup by gel permeation and silica gel chromatography with GC/ECD analysis has been tested for its suitability to determine these camphechlor congeners. The limit of determination found for each congener was about 5 μg/kg. The determination of these four congeners allows an unambiguous identification without specific cleanup (e.g. complete separation from PCBs or chlordanes) and a simple quantification of camphechlor residues, thus eliminating systematic errors resulting from different technical standards or detectors.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002169600014
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 3
    Digitale Medien
    Digitale Medien
    Preparation and structure of high-chlorinated bornane derivatives for the quantification of toxaphene residues in environmental samples (1993)
    Springer
    Fresenius' Zeitschrift für analytische Chemie 346 (1993), S. 779-785 
    Details
    ISSN: 1618-2650
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary The HRGC-determination of Taxophene® residues in the presence of other chlorinated hydrocarbons with similar retention times is often difficult. This problem can satisfactorily be overcome by using purely isolated high-chlorinated bornane derivatives (7–17) as standard. The method is highly selective for measuring toxaphene in complex environmental matrices, such as fish, and can also be used for evaluating the changes in the relative distribution that may have resulted from bioaccumulation and environmental transformation.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00321289
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 4
    Digitale Medien
    Digitale Medien
    Massenspektren donator-substituierter 4-Diphenylphosphinyl-trans-stilbene (1981)
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 323 (1981), S. 578-584 
    Details
    ISSN: 0021-8383
    Schlagwort(e): Chemistry ; Organic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Mass Spectra of Donor Substituted 4-Diphenylphosphinyl StilbenesThe electron impact induced fragmentation of six donor substituted diphenylphosphinyl stilbenes 1a-f have been determined. In general, independent fragmentation of the diphenylphosphinyl group and the donor substituent was found. Interaction between both substituents can be observed by the formation of ions with quinonoide structure and the loss of CO from the [M-1]-ion of the methoxy derivatives. Only few stilbene-typical ions have been observed.
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/prac.19813230407
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...