KINETICS OF PEROXIDASE-CATALYZED DECOLORATION OF ORANGE-II WITH HYDROGEN-PEROXIDE

The decoloration rate of Orange II is measured at 20 degrees C and pH 9.0 in the presence of hydrogen peroxide and such peroxidases (POD) as horseradish POD (HRP), POD from soybean (SPO), and arthromyces ramosu s POD (ARP). The decoloration rate of Orange II is expressed as pseudo -first order reaction kinetics for all PODs used. The rate constants i ncrease in the following order: SPO < HRP < ARP. Rate constant values for HRP and ARP are much greater than that for percarbonate. The diffe rences in rate constants between PODs can be explained in terms of the different reactivities of POD-intermediates for Orange II.