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Titrets® test kits use reverse titration to quantify concentrations in aqueous samples

The Vacu-vials® instrumental test kits employ the DPD chemistry and are accepted by the USEPA for wastewater and drinking water analysis.

Dissolved Oxygen in water test kits for environmental and drinking water applications (ppm range) employ the indigo carmine method. The reduced form of indigo carmine reacts with D.O. to form a blue product. The indigo carmine methodology is not subject to interferences from temperature, salinity, or dissolved gases such as sulfide, which plague users of D.O. meters.

Ceric sulfate is the titrant and ferroin is the end point indicator. The method is free from glycol interference in samples that contain up to 75% glycol, making it particularly applicable to systems that contain nitrite corrosion inhibitors. Results are expressed as ppm (mg/L) NaNO2.