Quantitative aspects of ESR and spin trapping of hydroxyl radicals and hydrogen atoms in gamma-irradiated aqueous solutions
The efficiency of 5,5-dimethylpyrroline-1-N-oxide (DMPO) and ..cap alpha..-(4-pyridyl-1-oxide)-N-tert-butylnitrone (POBN) to spin trap hydroxyl radicals and hydrogen atoms, respectively, was studied in ..gamma..-irradiated solutions where the radical yields are accurately known. The effects of dose, spin trap concentration, and pH and of the stability of the spin adducts on the spin-trapping efficiency were investigated. In degassed or N/sub 2/-saturated solutions the spin-trapping efficiencies were 35% for DMPO and hydroxyl radicals and 14% for POBN and hydrogen atoms. The low spin-trapping efficiency of DMPO may be explained by the reaction of hydroxyl radicals to abstract hydrogen from the DMPO molecule to produce carbon radicals as well as addition to the N=C double bond to form nitroxide radicals. For POBN the low spin-trapping efficiency for hydrogen atoms is explained in terms of addition reactions of hydrogen atoms to the aromatic ring and the pyridinium and nitrone oxygens.
- Research Organization:
- National Institutes of Health, Bethesda, MD
- OSTI ID:
- 6254818
- Journal Information:
- Radiat. Res.; (United States), Vol. 100:2
- Country of Publication:
- United States
- Language:
- English
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AQUEOUS SOLUTIONS
RADIOLYSIS
HYDROGEN
ELECTRON SPIN RESONANCE
TRAPPING
HYDROXYL RADICALS
ADDUCTS
COBALT 60
GAMMA RADIATION
NITROSO COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PH VALUE
PYRROLES
SPIN
ANGULAR MOMENTUM
AZOLES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CHEMICAL RADIATION EFFECTS
CHEMICAL REACTIONS
CHEMISTRY
COBALT ISOTOPES
DECOMPOSITION
DISPERSIONS
ELECTROMAGNETIC RADIATION
ELEMENTS
HETEROCYCLIC COMPOUNDS
INTERMEDIATE MASS NUCLEI
INTERNAL CONVERSION RADIOISOTOPES
IONIZING RADIATIONS
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
MAGNETIC RESONANCE
MINUTES LIVING RADIOISOTOPES
MIXTURES
NONMETALS
NUCLEI
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
PARTICLE PROPERTIES
RADIATION CHEMISTRY
RADIATION EFFECTS
RADIATIONS
RADICALS
RADIOISOTOPES
RESONANCE
SOLUTIONS
YEARS LIVING RADIOISOTOPES
400600* - Radiation Chemistry