Determination of ebselen-sensitive reactive oxygen metabolites (ebROM) in human serum based upon N,N′-diethyl-1,4-phenylenediamine oxidation

►We modified a simple assay in order to distinguish non-radical from radical species. ►Human serum was pretreated with ebselen to determine non-radical involvement. ►Non-radical species largely account for derum-mediated DEPPD oxidation. ►This assay can enhance understanding of contribution of different oxidants to disease.