Effects of aquatic humic substances on analysis for hydrogen peroxide using peroxidase‐catalyzed oxidations of triarylmethanes orp‐hydroxyphenylacetic acid

Abstract

A sensitive procedure is described for trace analysis of hydrogen peroxide in water. The procedure involves the peroxidase‐catalyzed oxidation of the leuco forms of two dyes, crystal violet and malachite green. The sensitivity of this procedure, as well as of another procedure based on the peroxidase‐catalyzed oxidation of p‐hydroxyphenylacetic acid (POHPA), is decreased in natural water samples and in aqueous solutions of aquatic humic substances. This decrease, which is less pronounced with the POHPA method, may be caused by competititve reactions of peroxidase intermediates with phenolic components of the humic substances. (This work was performed as part of an environmental exchange agreement between the United States and the Soviet Union).