Considerations in the spin trapping of superoxide and hydroxyl radical in aqueous systems using 5,5-dimethyl-1-pyrroline-1-oxide.

The superoxide radical spin adduct of the spin trap 5,5-dimethyl-lmine-l-oxide was found to be relatively unstable in aqueous solution. The half-life of the electron spin resonance signal is approximately 80 set at pH 6 and only about 35 set at pH 8. These observations as well as the possible reaction products of 0' that may develop in the time course of an experiment, must be considered whe a planning or interpreting data from a spin trapping experiment.