Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Rapid Communications in Mass Spectrometry 3 (1989), S. 323-328 
    ISSN: 0951-4198
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: The plasma desorption (PD) mass spectra of several enzymes and proenzymes are reported. Chymotrypsin and chymotrypsinogen both yield usable PD mass spectra; however, the single-chain chymotrypsinogen exhibits better sensitivity and less fragmentation than the multi-chain chymotrypsin. Porcine pepsinogen contains 11 more basic residues (lysine and arginine) than porcine pepsin, but this does not lead to an increase in positive ion response. In fact, the additional basic residues may hinder response by increasing the strength of the interaction between the protein and the nitrocellulose surface. A series of subtilisins showed comparable PD mass spectrometric, response despite the fact that they differ considerably in primary sequence. Finally, PD mass spectrometry was used to correct the previously reported mass of a heat-stable protease, a value that we found to be in error by almost 5000 Da.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Rapid Communications in Mass Spectrometry 3 (1989), S. 46-50 
    ISSN: 0951-4198
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Rapid Communications in Mass Spectrometry 4 (1990), S. 24-29 
    ISSN: 0951-4198
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: A simple method for off-line coupling of desorption mass spectrometry and capillary-zone electrophoresis (CZE) is described. Use of a “porous glass joint”, near the cathodic end of the CZE column, facilitates fraction collection in a manner similar to that used with liquid chromatography. This method allows independent optimization of both the CZE and mass spectrometry parts of the experiment. It is directly applicable to a number of desorption mass spectrometry methods (including plasma desorption (PD) and UV laser desorption (LD)). In the present study, PD mass spectrometry was used for eluant characterization. The fraction collection procedure is described, as is mass transfer through the porous glass joint. Detection limits are discussed and the approach is illustrated by analysis of a simple mixture of bradykinin derivatives. Finally, a brief comparison to current on-line CZE/mass spectrometric methods is presented.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 9 (1974), S. 359-364 
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The chemical ionisation mass spectra of a number of representative explosives have been obtained using hydrogen as reagent gas. Fragmentation modes of the protonated molecular ions tend to be simple although some rearrangements have been noted. Loss of a radical from an even electron parent ion has been observed. The use of ‘ghost spectra’ for confirmation of the molecular weight of the sample is stressed: these consist of ions of low abundance resulting from reactions between sample ions and sample molecules. Labelling studies were carried out using deuterium as reagent gas.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 11 (1976), S. 848-856 
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The electron impact mass spectra of some deuterium labelled 2-dimethylaminopyridines are consistent with hydrogen randomization within the dimethylamino group prior to the loss of the elements of methylenimine.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 1 (1968), S. 115-126 
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The mass spectra of a series of metal complexes of dibenzoylmethane have been rationalized. The paths of novel rearrangement reactions involving both hydrogen and oxygen migration may differ according to the type of metal atom in the complex. Further examples are proposed of the effect of metal valency changes in ion reactions.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 5 (1971), S. 1391-1397 
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Experimental evidence demonstrating reversible hydrogen transfer between specific positions in the molecular ions of anisole and o-toluic acid suggests stepwise mechanisms for the loss of CH2O and H2O, respectively. Added support for a stepwise mechanism for the loss of CH2O is found in the mass spectra of pyridine and quinoline analogues.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 6 (1972), S. 931-937 
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A review article is presented relating to the concept of valence-change in the mass spectra of metal-containing compounds. It is found that the modes of ion dissociation in these spectra are markedly dependent on the oxidation states normally assumed by the metal concerned and it is postulated that electron-transfer may be possible between the complexed metal atom and its ligands in the ion, such that the odd- or even-electron character of the ion is inter-changeable. Ion reactions such as the consecutive loss of two radicals are normally of low probability in the mass spectra of organic compounds, but are often observed in the mass spectra of metal-containing compounds and can be rationalized in terms of the valence-change concept. Convincing evidence for valence-change in some spectra is provided by the occurrence of reactions leading to the bare metal ion, or to the loss of neutral fragments containing the metal atom in a lower oxidation state than in the precursor molecule. Further applications of the concept may be found in the rationalization of the mass spectra of inorganic and organometallic compounds.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 13 (1978), S. 284-295 
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The ion currents due to products of selected ion reactions of toluene and 3-chlorophenol, occurring in the source or flight tube of a double focusing mass spectrometer for which the electric sector precedes the magnetic sector, have been represented by plotting them against two variables that reflect independently the effects of the sectors. The daughter ion produced from the molecular ion of 3-chlorophenol that decays by sequential losses of CO in the field free region preceding the electric sector and Cl· in the field free region preceding the magnetic sector gives rise to a peak with a distinctive shape on the resultant three-dimensional surface. A peak due to the daughter ion arising from the corresponding sequential losses of H· and C2H2 from the molecular ion of toluene could not be detected. A portion of the ion kinetic energy spectrum which would be recorded by a detector at the energy resolving slit is derived from the surface for 3-chlorophenol and is in satisfactory agreement with a published spectrum.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...