O-Cresolphthalein丨CAS 596-27-0

o-Cresolphthalein is widely used as a pH indicator, analytical reagent, and chemical intermediate in research and industrial applications. In analytical chemistry, it is employed to determine calcium concentrations in clinical samples, water, and food products due to its ability to form colored complexes with calcium ions. The compound is also applied in acid–base titrations as a colorimetric pH indicator, providing clear visual changes within specific pH ranges. Additionally, o-Cresolphthalein serves as a building block in the synthesis of dyes, pigments, and polymeric materials, as well as in research involving sensor development and chromogenic assays.

The compound offers several advantages due to its chemical structure and multifunctional properties. Its phenolic and phthalide groups provide strong complexation with metal ions, enabling sensitive and selective calcium detection. The indicator properties of o-Cresolphthalein allow for rapid and easy visual assessment of pH changes or ion concentration, enhancing efficiency in laboratory and quality control settings. It is chemically stable under normal storage conditions and compatible with common solvents, ensuring reproducible results. Furthermore, its ability to be derivatized and incorporated into polymers or dyes allows for flexibility in material science and analytical applications.