How enhanced molecular ions in Cold EI improve compound identification by the NIST library

2015 ◽  
Vol 29 (23) ◽  
pp. 2287-2292 ◽  
Author(s):  
Tal Alon ◽  
Aviv Amirav
Keyword(s):  
Molecular Ions ◽  
Compound Identification ◽  
Cold Ei

Identification of Rubber Additives by Field Desorption and Fast Atom Bombardment Mass Spectroscopy

1984 ◽  
Vol 57 (5) ◽  
pp. 1013-1022 ◽  
Author(s):  
Robert P. Lattimer ◽  
Robert E. Harris ◽  
Doyle B. Ross ◽  
Hugh E. Diem
Keyword(s):  
Molecular Weight ◽  
Mass Range ◽  
Molecular Ions ◽  
Organic Additives ◽  
Compound Identification ◽  
Mass Spectral ◽  
Rubber Compounds ◽  
General Answer ◽  
Background Ions ◽  
Normal Background

Abstract From the results presented here, it is clear that FD-MS and FAB-MS are very effective analytical methods for the identification of organic additives in extracts from rubber compounds. In the examples above, the molecular weight information provided by FD and FAB provided a nice complement to the IR data. In cases where IR could give only a general answer (i.e., a compound class), the mass spectral data provided a very specific compound identification. It is encouraging that all the samples examined gave useful spectra by both FD and FAB analysis. In most cases, the same information was obtained by both techniques. Certain compounds, however, were observed by FD but not by FAB (wax, oil, isocyanurate antioxidant). While FD provided only molecular weight information, FAB also provided fragmentation to aid in the confirmation of component assignments. Both the FD and FAB mass spectra were fairly complex for most of the extracts, but for different reasons. In FD, oil and wax oligomers gave many molecular ions over a wide mass range. FAB spectra, on the other hand, were somewhat cluttered due to the normal background ions produced by the sputtering process. With both techniques, however, the various components in some fairly complex mixtures were readily identified.

Doubly Charged Molecular Ions in GC–MS with Cold EI

2019 ◽  
Vol 31 (2) ◽  
pp. 347-354
Author(s):  
Ksenia J. Margolin Eren ◽  
Alexander B. Fialkov ◽  
Uri Keshet ◽  
Svetlana Tsizin ◽  
Aviv Amirav
Keyword(s):  
Molecular Ions ◽  
Cold Ei ◽  
Doubly Charged

Radiation less transitions in gas phase molecular ions

1980 ◽  
Vol 77 ◽  
pp. 705-718 ◽  
Author(s):  
Sydney Leach ◽  
Gérald Dujardin ◽  
Guy Taieb
Keyword(s):  
Gas Phase ◽  
Molecular Ions

THERMAL MODEL FOR THE DESORPTION OF (MOLECULAR) IONS INDUCED BY MeV HEAVY IONS

1989 ◽  
Vol 50 (C2) ◽  
pp. C2-237-C2-243 ◽  
Author(s):  
H. VOIT ◽  
E. NIESCHLER ◽  
B. NEES ◽  
R. SCHMIDT ◽  
CH. SCHOPPMANN ◽  
...  
Keyword(s):  
Heavy Ions ◽  
Thermal Model ◽  
Molecular Ions

Dissociative recombination of molecular ions in noble-gas plasmas

1992 ◽  
Vol 162 (1) ◽  
pp. 35 ◽  
Author(s):  
V.A. Ivanov
Keyword(s):  
Noble Gas ◽  
Dissociative Recombination ◽  
Molecular Ions

Dissociative recombination of electrons and molecular ions

1982 ◽  
Vol 136 (1) ◽  
pp. 25 ◽  
Author(s):  
Aleksandr V. Eletskii ◽  
Boris M. Smirnov
Keyword(s):  
Dissociative Recombination ◽  
Molecular Ions

Gaseous Molecular Ions

1992 ◽  
Author(s):  
Eugen Illenberger ◽  
Jacques Momigny
Keyword(s):  
Molecular Ions

Mass Spectrometry and Combinatorial Chemistry New Approaches for Direct Support-Bound Compound Identification

2001 ◽  
Vol 4 (4) ◽  
pp. 363-373 ◽  
Author(s):  
C. Enjalbal ◽  
D. Maux ◽  
J. Martinez ◽  
R. Combarieu ◽  
J-L. Aubagnac
Keyword(s):  
Mass Spectrometry ◽  
Combinatorial Chemistry ◽  
Compound Identification ◽  
New Approaches ◽  
Direct Support

Inductive effect in EI-mass spectra of some 5,6-dihalogenides and 5,6-halohydrins of 5α-cholestan-3β-ol and 3β-acetoxy-5α-cholestane

1982 ◽  
Vol 47 (11) ◽  
pp. 2946-2960 ◽  
Author(s):  
Antonín Trka ◽  
Alexander Kasal
Keyword(s):  
Mass Spectra ◽  
Inductive Effect ◽  
Molecular Ions ◽  
Hydroxyl Group ◽  
Halogen Atoms ◽  
Derivatives Of

Partial EI-mass spectra of 3β-hydroxy- and 3β-acetoxy-5α-cholestanes substituted in positions 5α-, 6β- or 5α,6β- with a hydroxyl group or halogen atoms (fluorine, chlorine, bromine) are presented. The molecular ions of 5α,6β-disubstituted derivatives of 3β-hydroxy-5α-cholestane (or of its 3-acetate) are considerably more stable than the corresponding monosubstituted derivatives if at least one of the pair of the vicinal substituents is chlorine or fluorine. This increase in stability, most striking in 5α- and 6β-fluoro compounds, is explained by the inductive effect.

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