Free Radicals by Mass Spectrometry. I. The Measurement of Methyl Radical Concentrations

1952 ◽  
Vol 20 (5) ◽  
pp. 907-914 ◽  
Author(s):  
F. P. Lossing ◽  
A. W. Tickner
Keyword(s):  
Mass Spectrometry ◽  
Free Radicals ◽  
Methyl Radical

Heats of formation of free radicals by mass spectrometry

1973 ◽  
Vol 95 (20) ◽  
pp. 6562-6566 ◽  
Author(s):  
D. K. Sen. Sharma ◽  
J. L. Franklin
Keyword(s):  
Mass Spectrometry ◽  
Free Radicals ◽  
Heats Of Formation

FREE RADICALS BY MASS SPECTROMETRY: X. THE IONIZATION POTENTIALS OF METHYL SUBSTITUTED ALLYL RADICALS

1956 ◽  
Vol 34 (3) ◽  
pp. 345-353 ◽  
Author(s):  
C. A. McDowell ◽  
F. P. Lossing ◽  
I. H. S. Henderson ◽  
J. B. Farmer
Keyword(s):  
Mass Spectrometry ◽  
Free Radicals ◽  
Electron Impact ◽  
Heat Of Formation ◽  
Ionization Potentials ◽  
Bond Dissociation Energies ◽  
Allyl Radical ◽  
Dissociation Energies ◽  
Allyl Halides ◽  
Vertical Ionization Potentials

The vertical ionization potentials of the β- and γ-methyl substituted allyl radicals as measured by electron impact are 8.03 ± 0.05 v. and 7.71 ± 0.05 v, respectively. From appearance potential data the following bond dissociation energies can be derived, assuming the dissociation processes to be free from complications:[Formula: see text]With assumptions about the structure of the ions produced by electron impact from the corresponding butenes the dissociation energies of the C4H7—H bonds in these latter compounds can be estimated, and the heats of formation of the corresponding radicals derived, namely:[Formula: see text]From data on the allyl halides we evaluate the heat of formation of the allyl radical to be:[Formula: see text]

scholarly journals New Methodologies for Qualitative and Semi-Quantitative Determination of Carbon-Centered Free Radicals in Cigarette Smoke Using Liquid ChromatographyTandem Mass Spectrometry and Gas Chromatography-Mass Selective Detection

2010 ◽  
Vol 24 (2) ◽  
pp. 58-71 ◽  
Author(s):  
AR Gerardi ◽  
WM Coleman
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Free Radicals ◽  
Cigarette Smoke ◽  
Selective Detection ◽  
Selected Ion Monitoring ◽  
Relative Quantitation ◽  
Liquid Chromatography Tandem Mass ◽  
New Methodologies

AbstractSeveral approaches were explored to develop a high throughput procedure for relative determination of 14 different carbon-centered free radicals, both acyl and alkylaminocarbonyl type, in cigarette smoke. Two trapping procedures using 3-cyano-2,2,5,5-tetramethyl-1-pyrrolidinyloxy, or 3-cyanoproxyl radical (3-CNP) were designed for this study: a) trapping in solution and b) trapping on a solid support which was a Cambridge filter pad. Fresh whole smoke and vapor phase smoke from mainstream cigarette smoke from Kentucky Reference Cigarettes 2R4F, as partitioned via an unadulterated Cambridge filter pad, were transferred into each trapping system in separate experiments. The 3-CNP coated Cambridge filter pad approach was shown to be superior to the impinger procedure as described in this study. Gas chromatography coupled with mass selective detection (GC-MS) was employed for the first time as an alternate means of detecting several relatively highly concentrated radical adducts. Liquid chromatography tandem mass spectrometry (LC-MS/MS) with precursor ion monitoring and selected ion monitoring (SIM) was used for detecting the large array of radicals, including several not previously reported: formyl, crotonyl, acrolein, aminocarbonyl, and anilinocarbonyl radicals. Relative quantitation was achieved using as external calibration standards of 4-(1-pyrrolidino)benzaldehyde and nicotine. It was determined that the yield of carbon-centered free radicals by reference cigarette 2R4F was approximately 265 nmoles/cigarette at 35 mL puff/60 sec interval/2 sec duration smoking conditions.

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