Patent ID: 8822719

Claim:
A method for detecting a concentration of peroxycarboxylic acid and/or hydrogen peroxide in a sanitizing composition and/or cleaning process comprising: providing an equilibrium peroxycarboxylic acid composition comprising a C 1 -C 22 peroxycarboxylic acid, a C 1 -C 22 carboxylic acid, hydrogen peroxide, and an alkyl aryl sulfonate fluorescent active compound, wherein the fluorescent active compound is stable in the equilibrium peracid composition; measuring a fluorescence response of said equilibrium peroxycarboxylic acid composition with an optical cell, wherein the fluorescence response measures the intensity of fluorescent emission of said fluorescent active compound; and determining a concentration of the peroxycarboxylic acid and/or the hydrogen peroxide of said equilibrium peroxycarboxylic acid composition based on the correlation of said fluorescent emission of said fluorescent active compound and the concentration of the peroxycarboxylic acid and/or the hydrogen peroxide.