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ARS Home » Southeast Area » New Orleans, Louisiana » Southern Regional Research Center » Food and Feed Safety Research » Research » Publications at this Location » Publication #144434


item Jacks, Thomas

Submitted to: Analytical Letters
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/1/2004
Publication Date: 5/1/2004
Citation: Jacks, T.J. 2004. Spectrofluorometric determination of hypohalites and peroxyacids using kojic acid. Analytical Letters. 37(6):1177-1184.

Interpretive Summary: It is important to be able to measure the strengths of chemicals used as oxidizers. This paper describes a new method for measuring the strengths of hypochlorite (the active ingredient in Clorox®) and other, related oxidizers. The method is based on the reaction of an oxidizer with a chemical to yield a product that fluoresces when illuminated with ultraviolet light. The intensity of the fluorescence is directly proportional to the strength of the oxidizer and is easily measured. In this manner, scientists, who are the principal users of this technological advance, are able to readily and reliably determine the strengths of oxidizers.

Technical Abstract: Hypochlorite reacted with kojic acid to form an intensely fluorescent product with excitation and emission wavelengths at 395 and 495 nm, respectively. Hypobromite, generated by reaction of hypochlorite or peroxyacetic acid with NaBr, also reacted with kojic acid to generate an identical fluorescent spectrum. A spectrofluorometric assay for hypochlorite and hypobromite based on this fluorogenic reaction with kojic acid is presented in this communication. Oxidation of bromide with peroxyacetic acid enables assay of the latter. Hydrogen peroxide had no effect on the assay results nor did it react with kojic acid per se unless peroxidase was present. In the latter case, the fluorescent spectrum was virtually identical to that from the hypohalite reaction, indicating similarity of fluorophore portion of the reaction product molecules.