CATALYTIC BEHAVIOR OF IRON(II)-OXIME COMPLEXES IN THE CHEMILUMINESCENCE REACTION OF LUMINOL WITH HYDROGEN-PEROXIDE

Chemiluminescence produced by the catalytic effect of iron(II)-oxime c omplexes on the oxidation of luminol by hydrogen peroxide was studied. This is a very fast chemiluminescence reaction and the emission spect rum is similar to that of peroxidase-catalysed chemiluminescence. Diff erent kinds of iron(II)-oxime complexes were compared and it was found that the symmetrical dioxime complex (four nitrogen ligands) has a hi gher catalytic activity than the asymmetric monooxime complex (two nit rogen and two oxygen ligands). The presence of EDTA can greatly accele rate the chemiluminescence reaction, which was considered to be a resu lt of the formation of a mixed-ligand complex. Other homologues of EDT A were tested and showed different degrees of enhancement. Optimum con ditions for the chemiluminescence reactions were examined. Combined wi th a flow-injection technique, trace amounts of hydrogen peroxide (2 X 10(-7)-1 X 10(-4) M) and, using glucose oxidase, glucose (0.79-160 mu g ml-1) can be determined by using the iron(II)-dimethylglyoxime compl ex as a typical catalyst. The detection limit of hydrogen peroxide was 1.3 X 10(-8) M. The relative standard deviation was 1% for the determ ination of 2 X 10(-7) M H2O2 (n = 11). The feasibility of utilizing th e proposed method for the determination of glucose in human serum was examined.