Spectrophotometric Determination of Hydrogen Peroxide with Bovine Hemoglobin as Catalyst

In a buffer mediun of 0.1 mol·L-1 citric acid solution mixed with 0.2 mol·L-1 Na2HPO4 solution of pH 4.8 and heated in a water bath at 43 ℃ for 60min, the oxidation of o-phenylenediamine by hydrogen peroxide was remarkably catalyzed by the present of bovine hemoglobin. Linear relationship between values of increase in absorbance (ΔA) and concentration of hydrogen peroxide was obtained in the range of 8.24×10-6-2.31×10-4mol·L-1 with detection limit (3s/k) of 4.50×10-8mol·L-1 . Based on these facts, a spectrophotometric method for determination of hydrogen peroxide with bovine hemoglobin as catalyst was proposed. The proposed method was applied to the determination of hydrogen peroxide in samples of disinfectant liquor and rainwater, RSD′s (n=5) calculated from the determined values were 0.081% and 1.6% respectively. The determined value of hydrogen peroxide in the disinfactant liquor was found to check quite well with the result found by titrimetry. Test for recovery was performed by standard addition method using these 2 samples as matrixes, values of recovery found were 99.3% and 97.3% respectively.