A composition, method and kit for quantifying the concentration of one peracid or the total concentration of two or more peracids in a water source are disclosed. In particular, an oxidation sensitive or peroxycarboxylic acid selective leuco dye is used to react only with one or more peroxycarboxylic acids in a water source but not with peroxide usually co-existing in the water source. Not only does the oxidation sensitive or peroxycarboxylic acid selective leuco dye react with peracid(s) but also the reaction generates a color species that can be used visually or through absorbance measurement to quantify the peracid concentration. The method disclosed here is not a titration method, it involves a simple mixing step. The kit or composition disclosed here does not utilize a catalyst, such as iodine.

Provided herein are methods and kits for detecting or quantifying a peroxymonosulfate (HS0.sub.5−) in an aqueous solution via electromagnetic radiation absorbance measurement.

A sensor is suggested, comprising a substrate and a first mixed layer arranged on the substrate, the first mixed layer comprising: a molecular probe; a sulfonic acid; and a hydrophilic compound; wherein the molecular probe is selected from: a triarylamine; a biphenyl diamine, a benzene diamine, a diaryl benzamide, and/or a triarylborane.

This invention is in the field of fluorescence imaging and relates to a new near infrared (NIR) reactive oxygen species (ROS) sensor designed with controlled fluorescence on-off switching mechanism.

Provided are a method and system for measuring hydrogen peroxide concentration in sample water collected from a prescribed position in a water treatment process and includes: collecting the sample water; measuring a concentration of a dissolved oxygen in the sample water or a treated water obtained by treating the sample water with the hydrogen peroxide decomposing device by first and second dissolved oxygen concentration measuring analyzers to obtain a corrected value that is a difference between the two dissolved oxygen concentration values; measuring the concentration of the dissolved oxygen in the sample and treated water by the first and second dissolved oxygen concentration measuring analyzers, respectively, and obtaining a measured value that is a difference between the dissolved oxygen concentration values; and calculating a corrected concentration of hydrogen peroxide from the measured value obtained during the measured value obtaining and the corrected value obtained during the corrected value obtaining.

Methods and systems are described for quantifying peroxyacid in a fluid by using spectrophotometry. Peroxyacid in the fluid is reacted with an iodide reagent and the absorbance of the reaction solution is measured. The absorbance can be measured at or near the isosbectic wavelength of iodine and triiodide, and the assay is useful to quantify peroxyacid that is present at high levels in fluids.

A peracetic acid decontamination chemical indicator including a substrate and an indicator composition disposed thereon, where the indicator composition comprises a colorant that changes color when exposed to a peracetic acid solution but does not change color when exposed to a hydrogen peroxide solution, an acidified hydrogen peroxide solution, or an acetic acid solution, and where the indicator composition does not include a transition metal salt or a halogen source, and methods of using the chemical indicator.

Methods and systems are disclosed for analyzing and treating a fluid containing a peroxyacid and/or peroxide. A method of analyzing the fluid includes introducing into the fluid a decomposition agent that catalyzes decomposition of the peroxyacid and/or peroxide into decomposition products including oxygen, then directly or indirectly measuring an amount of oxygen produced after introduction of the decomposition agent, and determining an amount of the peroxyacid and/or peroxide present in the fluid. The amount of peroxyacid and/or peroxide in the fluid can also be monitored and controlled by further adjusting the amount of the peroxyacid and/or peroxide in the fluid based on the determined amount thereof. A system for performing the methods includes a decomposition agent infusion device for introducing the decomposition agent into a fluid sample, and a sensor for directly or indirectly measuring an amount of oxygen produced after introduction of the decomposition agent.

The present application discloses a sensor for determining a measurand correlated with a concentration of at least one analyte belonging to the class of reactive oxygen species in a measuring fluid, the sensor including a sensor element having an indicator substance, wherein the indicator substance is oxidized into an oxidized form of the indicator substance by the at least one analyte, a means for generating a flow of current in the sensor element that causes a reduction of the oxidized form of the indicator substance and thereby regeneration of the indicator substance, an optical measuring sensor to detect measuring radiation influenced by the oxidized form of the indicator substance and to generate an electrical measuring signal using the influenced measuring radiation, and a sensor switch connected to the optical measuring sensor to receive the measuring signal and to ascertain a measured value of the measurand using the measuring signal.

A composition, method and kit for quantifying the concentration of one peracid or the total concentration of two or more peracids in a water source are disclosed. In particular, an oxidation sensitive or peroxycarboxylic acid selective leuco dye is used to react only with one or more peroxycarboxylic acids in a water source but not with peroxide usually co-existing in the water source. Not only does the oxidation sensitive or peroxycarboxylic acid selective leuco dye react with peracid(s) but also the reaction generates a color species that can be used visually or through absorbance measurement to quantify the peracid concentration. The method disclosed here is not a titration method, it involves a simple mixing step. The kit or composition disclosed here does not utilize a catalyst, such as iodine.