Mass spectrometric determination of spin adducts of hydroxyl and aryl free radicals

Abstract

G.l.c.–mass spectrometry has been applied in conjunction with e.s.r. to the identification of spin adducts produced by reactions between short-lived free radicals and nitrone spin traps. Thermally unstable spin adducts were converted into thermally stable and volatile trimethylsilyl derivatives suitable for g.l.c.–mass spectrometry. The structures of the trimethylsilylated spin adducts could be determined by observing molecular and fragment ion peaks as well as isotope peaks. Hydroxyl and aryl free radicals are identifiable by this method. Even if there were more than two different kinds of spin adduct, they could be easily separated by g.l.c and identified by their mass spectra.