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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 electron impact mass spectra of the N-[(S)-α-methoxy-α-trifluoromethylphenylacetyl] derivatives of amphetamine and several related compounds have been studied with the purpose of developing an assay for the enantiomers of the amines based on selected ion monitoring gas chromatography mass spectrometry. Stable isotope labeled analogs were used to elucidate the fragmentation pattern. The molecular ions are present in the spectra but are weak. The 1-phenyl-1-methoxy-2,2,2-trifluoroethyl cation is of significant intensity in all of the spectra. Other major fragmentations include a McLafferty rearrangement to give styrene radical ions, α-cleavage to nitrogen, and formation of benzyl cations derived from the amine or aminoester portion. An analytical procedure was developed for the simultaneous determination of the concentration of the enantiomers of amphetamine in rat urine. The method is based on selected ion monitoring gas chromatographic mass spectrometric analysis of the N-[(S)-α-methoxy-α-(trifluoromethyl)phenylacetyl] derivatives and uses amphetamine labeled with deuterium in the methyl group as internal standard. Using this procedure it was found that rats administered racemic amphetamine intraperitoneally excrete slightly more of the S enantiomer than of the R.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 11 (1976), S. 188-196 
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The methane chemical ionization mass spectra of dodecan-1, 10-dioic acid and the methyl ester show enhanced water and methanol elimination relative to monofunctional analogs. Elimination of acetic acid from 1,10-diacetoxydecane, however, was reduced relative to 1-acetoxydecane. This appears to be the result of bifunctional interactions. The steric requirement of this interaction is shown in an homologous series of dicarboxyl compounds. The change in interfunctional separation is shown to affect the proton and ammonium ion affinities in the ammonia chemical ionization spectra of the dicarboxyl compounds in a manner explained in terms of proton and ammonium ion complex formation. The observation is extended to various other functional groups.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 11 (1976), S. 197-206 
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Chemical ionization mass spectra of dicarboxylic acids and methyl esters show fragmentation and unimolecular reactions with reagent gases water, methanol, ammonia and methyl ether, which differ from those observed with hydrocarbon reagents methane and isobutane. These reactions involve exchange of the reagent gas for water or methanol of the dicarboxyl compounds as well as secondary exchange of both functions. An effort has been made to determine the mechanism of these reactions and to determine the structural requirements necessary for their occurrence.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
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