Simulation of electron impact mass spectra by charge exchange in chemical ionization mass spectrometry

1984 ◽  
Vol 56 (7) ◽  
pp. 1111-1114 ◽  
Author(s):  
Donald F. Hunt ◽  
P. Jane. Gale
Keyword(s):  
Mass Spectrometry ◽  
Electron Impact ◽  
Charge Exchange ◽  
Mass Spectra ◽  
Chemical Ionization ◽  
Ionization Mass Spectrometry ◽  
Chemical Ionization Mass Spectrometry ◽  
Ionization Mass ◽  
Electron Impact Mass ◽  
Impact Mass

Chemical Ionization Mass Spectrometry of Organophosphorus Insecticides

1974 ◽  
Vol 57 (5) ◽  
pp. 1050-1055 ◽  
Author(s):  
Roy L Holmstead ◽  
John E Casida
Keyword(s):  
Mass Spectrometry ◽  
Electron Impact ◽  
Mass Spectra ◽  
Chemical Structure ◽  
Chemical Ionization ◽  
Ionization Mass Spectrometry ◽  
Chemical Ionization Mass Spectrometry ◽  
Ionization Mass ◽  
Organophosphorus Insecticides ◽  
Fragmentation Patterns

Abstract The chemical ionization (CI) mass spectra of 15 important organophosphorus insecticides and 14 of their major metabolites are discussed in relation to the effect of chemical structure on fragmentation patterns. The fragments obtained with CI are sometimes quite different from those formed on electron impact and, in general, simpler spectra are obtained with CI.

Charge exchange mass spectra of some C5H10 isomers

1981 ◽  
Vol 59 (12) ◽  
pp. 1753-1759 ◽  
Author(s):  
Yip Hoi Li ◽  
Jan A. Herman ◽  
Alex. G. Harrison
Keyword(s):  
Electron Impact ◽  
Charge Exchange ◽  
Mass Spectra ◽  
Chemical Ionization ◽  
Relative Energy ◽  
Ionization Mass ◽  
Single Source ◽  
Fragmentation Pathways ◽  
Electron Impact Mass ◽  
Impact Mass

Reagent gas systems are described for use in a single-source chemical ionization mass spectrometer which permit charge exchange mass spectra to be obtained using CS2+•(∼10.2 eV), COS+•(11.2 eV), Xe+•(∼12.5 eV), CO+•(14.0 eV), N2+•(15.3 eV), and Ar+• (15.8 eV) (recombination energies in brackets) as the major reactant ions. Using these reagent gas systems the charge exchange mass spectra of cyclopentane, 1-pentene, 3-methyl-l-butene, 2-methyl-l-butene, 2-pentene, and 2-methyl-2-butene have been obtained. It is shown that these spectra can be used to construct breakdown graphs which adequately depict the relative energy dependences of the fragmentation pathways and rationalize the 70 eV electron impact mass spectra.

Chemical Ionization Mass Spectrometry of N-Methylcarbamate Insecticides, Some of Their Metabolites, and Related Compounds

1975 ◽  
Vol 58 (3) ◽  
pp. 541-547 ◽  
Author(s):  
Roy L Holmstead ◽  
John E Casida
Keyword(s):  
Mass Spectrometry ◽  
Electron Impact ◽  
Mass Spectra ◽  
Chemical Ionization ◽  
Ionization Mass Spectrometry ◽  
Chemical Ionization Mass Spectrometry ◽  
Ionization Mass ◽  
Related Compounds

Abstract The chemical ionization (CI) mass spectra with methane as the reagent gas are reported for 25 N-methylcarbamato insecticides or related compounds. The [M + 1]+ ions in the CI spectra are larger than the parent ions in the corresponding electron impact (EI) spectra of N-methyl- and N,N-dimethylcarbamates, but the contrary is true with N-hydroxymethylcarbamates. CI but not EI fragmentation of substituted- phenyl N-hydroxymethylcarbamates [ROC(0)NHCH2OH] appears to involve a 4-membered [ROC(0)NHCH2]+ intermediate which rearranges to give a [ROCH2]+ fragment. Other fragmentations unique to the CI spectra are also discussed.

Electron Impact and Chemical Ionization Mass Spectrometry of Some Butyrophenones

1977 ◽  
Vol 60 (1) ◽  
pp. 21-26 ◽  
Author(s):  
Jos G Leferink ◽  
Robert A A Maes
Keyword(s):  
Mass Spectrometry ◽  
Electron Impact ◽  
Mass Spectra ◽  
Chemical Ionization ◽  
Impact Ionization ◽  
Electron Impact Ionization ◽  
Ionization Mass Spectrometry ◽  
Chemical Ionization Mass Spectrometry ◽  
Ionization Mass

Abstract The mass spectra of some butyrophenoncs are presented. Electron impact ionization and chemical ionization with isobutane as the reagent gas are compared. The chemical ionization spectra show the quasi molecular ion (M + H)+ to be the most abundant ion. Important fragments in the electron impact spectra are discussed for easy determination of other similar compounds.

Occurrence of 3-acetamido-3,6-dideoxy-4-O-miethyl-L-glucose in the O-polysaccharide of Vibrio anguillarum

1985 ◽  
Vol 63 (12) ◽  
pp. 1265-1267 ◽  
Author(s):  
Joseph H. Banoub ◽  
Francis Michon ◽  
Fred Cooper
Keyword(s):  
Mass Spectrometry ◽  
Electron Impact ◽  
Chemical Ionization ◽  
Vibrio Anguillarum ◽  
Amino Sugar ◽  
Bacterial Lipopolysaccharide ◽  
Ionization Mass Spectrometry ◽  
Chemical Ionization Mass Spectrometry ◽  
Ionization Mass

The amino sugar 3-acetamido-3,6-dideoxy-4-O-methyl-L-glucose has been characterized in the O-polysaccharide obtained from the bacterial lipopolysaccharide of Vibrio anguillarum. The identity of 1,2,5-tri-O-acetyl-3-acetamido-3,6-dideoxy-4-O-methyl-L-glucitol has been established by electron-impact and chemical-ionization mass spectrometry and by a labeling procedure.

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