The hydroxyl and some alkoxyl spin adducts of 5,5-dimethylassignment of EPR spectra have been encountered ( 5) ; 1-pyrroline 1-oxide (DMPO) are difficult to assign due to the some studies produced clearly contradictory results and remarkable similarity of their EPR spectra. The utility of resolving have been thoroughly reinvestigated ( 6, 7 ) . Therefore, superhyperfine (SHF) structure followed by computer simulations there are limitations currently considered in this method has been demonstrated to assist in the assignment of EPR spectra and continuous efforts are being made to enhance the suitwith close values of hyperfine splitting constants, e.g., DMPO/ ability of DMPO or its derivatives as a spin trap for O-β’ OH and DMPO/ β’ OR. Here, β’ OR is the alkoxyl radical derived centered radicals ( 8 -10 ) . There are two popular direcfrom thermal decomposition of 2,2-azobis (2-amidinopropane) tions in these studies: synthesis of novel spin traps and hydrochloride (AAPH). In addition, two other spin traps, derivaimprovement in spectroscopic technique. tives of 2H-imidazole 1-oxide, namely, 2,2,4-trimethyl-2H-imidaz-Recently, two promising spin traps, derivatives of 2Hole 1-oxide (TMIO) and 2,2-dimethyl-4-phenyl-2H-imidazole 1oxide (DMPIO), have been used in a model study to develop a imidazole 1-oxide, namely, 2,2,4-trimethyl-2H-imidazole 1procedure for distinguishing between oxygen-centered spin adoxide (TMIO) and 2,2-dimethyl-4-phenyl-2H-imidazole 1ducts. These results are compared with those for DMPO. TMIO oxide (DMPIO) have been developed and compared with and DMPIO spin traps provide more distinguishable individual DMPO (11, 12