DMPO Spin Trapping of Superoxide Anion in Strong Alkaline DMSO Solution

Abstract Superoxide anion (O2•−), generated in a strong alkaline DMSO solution and detected by direct 77 K EPR, was trapped with 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) and the resultant nitroxide radical, DMPO/O2•−, has been found to be sufficiently stable for the subsequent EPR detection.