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  • 1
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 14 (1987), S. i 
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
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  • 3
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 14 (1987), S. 1-4 
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Amino acids can be identified unambiguously in form of their dansylated methyl esters by combination of thin-layer chromatography on polyamide and subsequent mass spectrometry without prior substance elution from the chromatographic polyamide carrier. The evaporation intensity of the amino acid derivatives is sufficient to get excellent mass spectra with significant structural information also with very small amounts of starting material (picomole level), which guarantee a high separation power in the TLC step. Besides the methylester derivatives, in part, products additionally methyl substituted at the sulfonamide nitrogen could be separated.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 14 (1987), S. 5-7 
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The simple combination of thin-layer chromatography on polyamide with subsequent mass spectrometry of the separated compounds together with the carrier material has been employed for unambiguous identification of individual dipeptides in a mixture. The dipeptides were analysed in the form of their dansyl methyl ester derivatives. The appearance of molecular ions in the electron impact mass spectra simultaneously with the ions dans-NH=CHR⌝+ indicating the corresponding N-terminal amino acid residue enables a rapid and sensitive structure elucidation of the dipeptides. The chromatography and mass spectrometry can be performed with 0.2-0.3 nmol dipeptide.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 14 (1987), S. 9-15 
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Fast atom bombardment (FAB) followed by collisional activation (CA) mass spectrometry was used for structural analysis of steroidal oligoglycosides, containing two to four sugar units. In the molecular ion region of the FAB mass spectra of these underivatized natural products, intense protonated molecular ions were observed. The collisional activation spectra of these mass selected ions yield more sequence information than FAB mass spectra and are not contaminated with interfering peaks originating from impurities or matrix.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 14 (1987), S. 23-27 
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The DNA base uracil was derivatized with pentafluorobenzoyl chloride, followed by methylation with methyl iodide in the presence of N,N-dimethylformamide (DMF). In addition to a 3-pentafluoro-benzoyl-1 -methyl derivative of uracil, GC/MS analysis of the reaction mixture revealed the formation of an unusual product, whose molecular weight was 12 U higher than that of the prior derivative. This unexpected product has been identified as the 3-(para-methoxytetrafluorobenzoyl)-1-methyl derivative of uracil. Isotopic labeling and related experiments have revealed that the DMF solvent contributes the oxygen atom of the methoxy group that replaces the para fluorine atom. This work allowed a single derivative to be obtained for the methylation reaction by changing the solvent to acetonitrile.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 14 (1987), S. 17-22 
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A highly sensitive (subpicomole level), structure-specific method of analysis has been developed for characterizing and quantitating the dinucleotide thymidylyl(3′ → 5′)thymidine methyl phosphotriester by desorption chemical ionization tandem mass spectrometry. The methodology can be applied to related compounds such as the parent dinucleotide and employs either positive or negative ionization mass spectra or daughter spectra. The procedure allows specification of the site of methyl attachment.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 14 (1987), S. 39-42 
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The application of gas chromatography/mass spectrometry to three thermally labile phenylurea pesticides is reported. Using alcohols as solvents the decomposition of the pesticides is followed by a reaction in which esters of N-(3,4-dichlorophenyl)carbamic acid are formed. As these reactions occur during the gas chromatographic analysis, it is the esters which are identified in the mass spectrometer. The methyl ester is itself a pesticide so an erroneous conclusion about the original pesticide could be reached when methanol is the solvent.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 14 (1987), S. 43-45 
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The ions produced by 252Cf plasma desorption are detected by Fourier transform ion cyclotron resonance techniques. Results for CsI and N,N,N-trimethyl-p-aminophenolate iodide show the feasibility of the technique with high resolution (up to 11 000 at m/z 23) and good signal-to-noise ratio (up to 726).
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 14 (1987), S. 29-38 
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Fast atom bombardment mass spectrometry (FAB MS) and fast atom bombardment mass spectrometry-mass spectrometry (FAB MS/MS) were used to study the monovalent glycoside polyether antibiotics maduramicin α, β and δ and the maduramicin α salts, their derivatives and degradation products. Also, representative compounds from three major classes of polyether antibiotics were studied: the monovalent polyethers, nigericin and monensin A, the divalent polyether lasalocid A and the monovalent glycoside polyethers septamycin, BL580 δ, etheromycin and carriomycin. The respective FAB fragment and decomposition ions were correlated with the known structures. The FAB spectra of all the polyethers contained metal-adduct molecular ions. Protonated molecular ions were absent. All the polyethers having a β-hemiketal carboxylic acid group produced an abundant ion, often the base peak of the spectra, 62 daltons less than the corresponding metal-adduct molecular ion. The gas phase mechanism proposed for the formation of this fragment ion is an unusual unimolecular reaction which is initiated by an intramolecular proton transfer from the carboxylic acid to the hydroxy group of the β-hemiketal, and, then followed by the concerted losses of water and carbon dioxide to produce the corresponding polyether olefin.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
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