scholarly journals Mass-analysed ion kinetic energy and collisionally induced dissociation mass spectra of clusters of acetylated xylo-oligosaecharides with protonated ammonia and methylannine

1992 ◽  
Vol 27 (11) ◽  
pp. 1322-1324 ◽  
Author(s):  
V. Kovàčcik ◽  
J. Hirsch ◽  
P. Kováč ◽  
H.-Fr. Grützmacher
Keyword(s):  
Kinetic Energy ◽  
Mass Spectra ◽  
Ion Kinetic Energy

The ion kinetic energy and mass spectra of isomeric methyl indoles

1972 ◽  
Vol 6 (1) ◽  
pp. 33-37 ◽  
Author(s):  
S. Safe ◽  
W. D. Jamieson ◽  
O. Hutzinger
Keyword(s):  
Kinetic Energy ◽  
Mass Spectra ◽  
Ion Kinetic Energy ◽  
Isomeric Methyl

The Ion Kinetic Energy Spectra of Benzyl Fluoride and the Isomeric Fluorotoluenes

1974 ◽  
Vol 52 (6) ◽  
pp. 867-869 ◽  
Author(s):  
S. Safe ◽  
W. D. Jamieson ◽  
D. J. Embree
Keyword(s):  
Mass Spectrometry ◽  
Kinetic Energy ◽  
Mass Spectrometer ◽  
Aromatic Compounds ◽  
Mass Spectra ◽  
Energy Spectra ◽  
Model Compounds ◽  
Free Region ◽  
Field Free Region ◽  
Ion Kinetic Energy

One of the classical problems in mass spectrometry is the structure and formation of the C7H7+ and XC7H6+ ions which are generated in the mass spectra of alkylbenzenes and many other aromatic compounds. The intermediacy of both symmetrical tropylium ion structures and unsymmetrical benzyl ions has been postulated using a number of different approaches. We have investigated this problem using ion kinetic energy spectroscopy, a relatively new technique, with the isomeric fluorobenzenes and benzyl fluoride as model compounds. Our results indicated incomplete substituent (i.e. fluorine) scrambling in the first field-free region of the mass spectrometer and thus incomplete equilibration in the decomposing FC7H6+ ions and these conclusions are in contrast to results obtained using other techniques.

Ion Kinetic Energy Determinations in Radio-Frequency Glow Discharge Mass Spectrometry

1995 ◽  
Vol 49 (7) ◽  
pp. 917-926 ◽  
Author(s):  
Paula R. Cable ◽  
R. Kenneth Marcus
Keyword(s):  
Kinetic Energy ◽  
Glow Discharge ◽  
Radio Frequency ◽  
Source Region ◽  
Potential Method ◽  
Operating Conditions ◽  
Atmospheric Plasma ◽  
Radio Frequency Glow Discharge ◽  
Ion Trajectory ◽  
Ion Kinetic Energy

Radio-frequency glow discharge (rf-GD) sources produce an abundance of both atoms and ions. For the mass spectrometric application of the glow discharge technique, knowledge of the ion kinetic energies is required to optimize extraction and focusing of ions from the source region into the analyzer. This paper details kinetic energies experimentally determined with the use of the “retarding potential” method. For this study, the analyzer quadrupole of a double-quadrupole mass spectrometer was positively biased to act as a repeller. Ion kinetic energies (IKEs) determined for a variety of discharge and analyzer operating conditions ranged from 12.5 eV to 25.0 eV for 63Cu+. Kinetic energy measurements were confirmed from ion trajectory simulations and follow closely the experimental values for identical analyzer conditions and initial IKEs. Results of this study indicate that the conditions under which ions are formed (plasma conditions) affect IKEs and energy spreads to a greater extent than analyzer parameter variations. Different from atmospheric plasma sources, IKEs for rf-GD species do not vary as a function of ion mass/identity. Evidence is also given in support of a slight mass biasing owing to the transmission properties of double-quadrupole analyzers. The findings detailed herein demonstrate the effects of rf modulation on both ion kinetic energy values and distributions.

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