Photochemical method for the determination of hydrogen peroxide and glucose

Abstract

Reduction of hydrogen peroxide was achieved with leuco-phloxin in the presence of haematin. The leuco dye was generated through the photochemical reaction between phloxin and ethylenediaminetetraacetic acid. The method involves measuring the time to reach the end-point of the photochemical titration, i.e., the photolysis time necessary for the total reduction of the peroxide. The method can be extended to the determination of substrate–enzyme systems that produce hydrogen peroxide, e.g., glucose–glucose oxidase. The assay is linear between 0.12 and 4.61 µg cm^–3 for hydrogen peroxide (r= 0.9992) and between 3.99 and 43.2 µg cm^–3 for glucose (r= 0.9989). The detection limit, defined as three times the standard deviation of the reagent blank, was 0.03 µg cm^–3 for hydrogen peroxide and 1.0 µg cm^–3 for glucose.