Trisodium citrate is an inorganic compound with chemical formula Na3C6H5O7. It is commonly referred to as sodium citrate. It has a saline taste and a mildly tart flavour, and because of this, it is known as “sour salt.” It is basically the natural tribasic salt of citric acid and its IUPAC name is trisodium;2-hydroxypropane-1,2,3-tricarboxylate. The anhydrous for of trisodium citrate occurs as white, granular crystals or as a white, crystalline powder. It is completely soluble in water and practically insoluble in ethanol (96 %). It is a non-toxic, neutral salt with low reactivity. It is chemically stable if stored at ambient temperatures. Trisodium citrate anhydrous is fully biodegradable and can be disposed with regular waste or sewage.
Trisodium citrate anhydrous is produced through dehydration of trisodium citrate dihydrate. Using a dehydration process, water molecules are removed without affecting the original crystal matrix. This lead to the formation of crystals with a porous matrix which allows it to act as carrier of organic/inorganic substances for applications such as perfumes.
The primary use of trisodium citrate is as a food additive for imparting flavour and acting as a preservative. Its most popular use as a flavouring agent is in club sodas, ready to drink beverages and drink mixes. It is also used as a buffer to regulate acidity and resist changes in pH in food products such as gelatin desserts, milk, etc.
It is used as an anticoagulant in blood transfusions, blood collection tubes as well as the preservation of blood in blood banks. It is also used as an osmotic laxative and an antacid. Other uses includes relieving discomfort in urinary tract infections, reducing acidosis in distal renal tubular acidosis.
It is used in boiler descaling for effectively removing the carbonate scale from boilers without removing them from operation and cleaning automobile radiators.