LUMINOL OXIDATION IN DETERGENT-FREE MICROEMULSIONS (HEXANE-ISOPROPANOL-WATER) CATALYZED BY HORSERADISH-PEROXIDASE OR HEMIN

Luminol oxidation by hydrogen peroxide catalyzed by horseradish peroxi dase and hemin in the microemulsions hexane-isopropanol-0.02 M borate (pH 9.5) and hexane-isopropanol-0.04 M NaOH, respectively, has been in vestigated. The chemiluminescence reaction was optimized with respect to water content, pH, and the concentrations of luminol and H2O2. Cycl ohexanol (4-10%) added to the microemulsions increased the maximum che miluminescence intensity by factors of 1.5 and 2 for peroxidase and he min, respectively The merits of using microemulsions as media for lumi nol oxidation instead of water, the inhibition by excess H2O2, and the overall reaction mechanism are discussed