Rapid quantitative determination of hydrogen peroxide by oxidation decolorization of methyl orange using a Fenton reaction system

In this study, a sensitive and rapid method for hydrogen peroxide (H2O2) determination has been developed with the aid of oxidation decolorization of methyl orange (MO) by using Fenton reactions, because the decolorization extent of MO solution (at the maximum absorption wavelength of 507 nm) is proportion to the concentration of H2O2. Under optimum conditions, this spectrophotometric method for the H2O2 analysis yields a dynamic range of H2O2 concentration from 5.0 × 10−7 to 1.0 × 10−4 mol L−1 (r = 0.997) and a detection limit (3σ/k) of 2.0 × 10−7 mol L−1. This method for the determination of H2O2 (0.04 mmol L−1) is able to tolerate the interference from NaCl (0–5.0 mmol L−1), Na2SO4 (0–5.0 mmol L−1), MgCl2 (0–5.0 mmol L−1), sodium humate (0–0.1 mmol L−1), benzene (0–0.2 mmol L−1), toluene (0–0.2 mmol L−1), chlorobenzene (0–0.2 mmol L−1) and chloroform (0–0.2 mmol L−1). The analysis results for practical rainwater samples are in good agreement with the classical N,N-diethyl-p-phenylenediamine (DPD) method for H2O2 determination.