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  • 1
    ISSN: 0306-042X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The major fragmentation pathways of eight isomeric androstane-3,17-diols, as their bis-t-butyldimethylsilyl ethers, were elucidated by linked scanning of the magnetic and electric fields in a double focusing mass spectrometer. Four competing pathways were observed, each characterized by losses of alkylsilanol moieties from a common [M-C4H9]+ precursor. Pronounced differences in the spectra obtained by linked scans complement the coventional mas spectra in the differentiation of the isomeric structures.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The fragmentation of the methyl oxime, tert-butyldimethylsilyl derivatives of androstanolones under electron impact is strongly directed by the derivatized functional groups. The relative importance of the few major fragmentation pathways varies between positional isomers and stereoisomers. High resolution selected ion monitoring of [M - C4H9]+, and metastable peak monitoring of [M - C4H9]+ → [M - C4H9 - H(CH3)2SiOH]+, may both be used for high sensitivity analysis.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 7 (1980), S. 500-504 
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Highly selective techniques of gas chromatography mass spectrometry have been used in the unequivocal identification of salivary steroids at concentrations ranging from 20 pg ml-1 to 20 ng ml-1. Oestradiol-17 β, for example, has been identified in pregnancy saliva by gas chromatography high resolution mass spectrometry selected ion monitoring of the bis-TMS ether and by gas chromatography mass spectrometry metastable peak monitoring of the bis-tert-butyldimethylsilyl ether. Dehydroepiandrosterone sulphate has been identified in saliva, following enzymic hydrolysis, by gas chromatography high resolution mass spectrometry selected ion monitoring of the tert-butyldimethylsilyl ether and methyl oxime tert-butyldimethylsilyl ether. These initial analyses have been designed to guide the development of routine immunoassay procedures which may subsequently be validated by comparison with reference gas chromatographic mass spectrometric methods.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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