N-ethyl-N-(3-sulfopropyl)-3-methylaniline sodium salt (TOPS), which is one of the new Trinder's color reagents, and the appearance is white crystalline powder. Because of its molecular structure and the sulfopropyl group on the single atom connected to the benzene ring, there is one less hydroxyl group with a slightly stronger stability, high water solubility, and high detection sensitivity. It is widely used in diagnostic and biochemical testing, mainly for the colorimetric determination of uric acid and cholesterol; when used as a water-soluble reagent, it can be used to determine hydrogen peroxide by enzymatic photometry.
