This specialty chemical, known as 3-(N-Ethyl-3-methylanilino)-2-hydroxypropanesulfonic acid sodium salt, is primarily utilized as a chromogenic substrate in enzymatic and spectrophotometric assays for the determination of hydrogen peroxide (H2O2). In peroxidase-coupled reactions, it undergoes oxidation in the presence of H2O2 and peroxidase enzyme, producing a colored product that enables quantitative measurement via absorbance at specific wavelengths (typically around 505-515 nm). Its sulfonic acid sodium salt form enhances water solubility, making it ideal for aqueous-based biochemical and analytical applications. With a purity of ≥98%, it is suitable for research and diagnostic purposes in clinical chemistry, environmental monitoring, and food safety testing where H2O2 levels need to be assessed.