Tetrasodium pyrophosphate, also called sodium pyrophosphate, tetrasodium phosphate or TSPP, is an inorganic compound with the formula Na4P2O7. As a salt, it is a white, water-soluble solid. It is composed of pyrophosphate anion and sodium ions.
Molar mass: 446.06 g/mol
Appearance: Colorless or white crystals
Density: 2.534 g/cm3
Melting point: 988 °C (1,810 °F; 1,261 K) (anhydrous);79.5 °C (decahydrate)
Boiling point: decomposes
Solubility in water:2.61 g/100 mL (0 °C);6.7 g/100 mL (25 °C);42.2 g/100 mL (100 °C)
Solubility: insoluble in ammonia, alcohol
Refractive index (nD):1.425
Crystal structure:monoclinic (decahydrate)
Sodium pyrophosphate decahydrate is used as a buffering agent, an emulsifier, a thickening agent, a food additive and a dispersing agent. It acts as a tartar control agent in tooth paste and dental floss and is used to remove calcium and magnesium from saliva, thereby avoiding its deposition on teeth. It is utilized in detergents to prevent deposition on cloth. It is useful in the preparation of an EDTA-sodium pyrophosphate extraction buffer for microcystin analysis of soil samples. In antimicrobial studies, it is used as a chelating agent.