DETECTION OF SUPEROXIDE ANION FROM THE REACTION OF OXYHEMOGLOBIN AND PHENYLHYDRAZINE USING EPR SPECTROSCOPY

The low temperature EPR spectrum of a quickly reacted mixture of oxyhemoglobin and phenylhydrazine was studied. With the use of a computer, the spectral contribution of methemoglobin in the region of g=2 was subtracted. The remaining spectrum was that of an axial free radical (g⊥=2.00, g{norm of matrix}=2.06) having the magnetic parameters of superoxide anion. In the presence of superoxide dismutase, this axial radical was not seen, confirming that superoxide anion is indeed generated by the reaction. © 1979 Birkhäuser Verlag.