Selective determination of hydrogen peroxide in household products using its molecular recognition by a dinuclear iron(III) complex

Abstract

A selective method for the determination of hydrogen peroxide in the presence of other oxidants is presented. The formation of a coloured adduct in the reaction of a dinuclear iron(III) complex with hydrogen peroxide is used for the quantification of the peroxide. The reaction product is detected at wavelengths between 570 and 600 nm. The major advantage of the method is the immediate reaction. Other peroxides exhibit little interfence, typically contributing to an error of 0.1% for the same concentration. The method was optimized for the determination of hydrogen peroxide in household products using microplate spectrophotometry. The limit of detection is 3 µmol l^–1 (100 ppb) under these conditions. Calibration functions are linear over the range 9–300 µmol l^–1 (300 ppb–10 ppm). The method was compared with established methods for peroxide analysis, including the spectrophotometric titanyl method and an HPLC method based on the oxidation of triphenylphosphine. The method described is suitable for the analysis of real samples.