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.

The disclosed hydrogen peroxide indicator includes a substrate on which is disposed an indicator composition that includes at least one of a select group of indicator compounds and a catalyst. As a result of contact with hydrogen peroxide, the indicator composition changes color, even from colorless to having a visually observable color, thereby providing an indication of the presence of hydrogen peroxide.

An analytical process for detecting compounds in a sample suspected of containing a peroxide-based compound, a nitrate-based compound, a nitrotoluene-based compound, or a nitramine-based compound includes treating the sample with a superbase and then contacting the sample with a composition. The composition includes or consists of a Ni-porphyrin and an acid and optionally an acid stable solvent.

A method for determining the concentration of a compound in ultrapure water is provided. The method includes dividing the ultrapure water into a first part and a second part and decomposing the compound in the first part, so that the first part includes a characteristic substance. The method also includes measuring a first concentration of the characteristic substance in the first part and a second concentration of the characteristic substance in the second part and calculating the difference between the first concentration and the second concentration. The method further includes obtaining the concentration of the compound in the ultrapure water based on the difference.

The disclosed hydrogen peroxide indicator includes a substrate on which is disposed an indicator composition that includes at least one of a select group of indicator compounds and a catalyst. As a result of contact with hydrogen peroxide, the indicator composition changes color, even from colorless to having a visually observable color, thereby providing an indication of the presence of hydrogen peroxide.

An analytical process, which preferably is a one-step process, for detecting in a sample peroxide-based explosives, and/or nitrate-based explosives, the process comprising contacting a sample suspected of containing a peroxide-based compound, especially a peroxide-based explosive, or a nitrate salt, especially a nitrate-based explosive, with a composition comprising a Ni-porphyrin, an acid and preferably an acid-stable solvent.