Highly Sensitive Determination of Hydrogen Peroxide with Hemoglobin as Catalyst
Wang Quanlin 1, Liu Zhihong 2, Cai Ruxiu 2, Lü Gongxuan *1 1(State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000) 2(Department of Chem
Hemoglobin (Hb) was used as a peroxidase substitute in the catalytic oxidation of p cresol by H 2O 2. The peroxidatic characteristics of Hb and enzymatic kinetics were studied. The results indicate that the catalytic activity of Hb as a peroxidase substitute is higher than other peroxidase mimics (e.g. hemin,β cyclodextrin (β CD) hemin, etc.). A sensitive spectrofluorimetric method for the determination of trace H 2O 2 was proposed based on the catalytic effect of Hb on the reaction of p cresol and hydrogen peroxide. The maximum emission wavelength of the product is located at 427nm with excitation wavelength at 318nm under the optimal conditions, the calibration graph is linear in the range of 3.19×10 -8 ～3.19×10 -6 mol/L H 2O 2 with a detection limit of 8.8×10 -10 mol/L. The relative standard deviation of eleven replicate measurements is 2.1% for the determination of 5.32×10 -7 mol/L H 2O 2. This method has been applied to determine H 2O 2 in rainwater with satisfactory results.