Determination of hydroxyl radical in Fenton system

Under visible light illumination, 2,3-diaminophenazine (DAPN) was generated from the oxidation of o-phenylenediamine (OPDA) in Fe3+/H2O2 solution. Hydroxyl radical (OH) produced in this system was determined by directly measuring the concentration of DAPN. In comparison with the traditional methods, the determination is more accurate and simple.