Sodium citrate is the sodium salt of citric acid. It is white, crystalline powder or white, granular crystals, slightly deliquescent in moist air, freely soluble in water, practically insoluble in alcohol. Like citric acid, it has a sour taste.
From the medical point of view, it is used as alkalinizing agent. It works by neutralizing excess acid in the blood and urine. It has been indicated for the treatment of metabolic acidosis.
The main functions of citric acid and the citrates in foods and beverages can be summarized as follows:
Store in closed container in cool, dry place & protect from light, heat dust & other contaminants.
Sodium citrate is chiefly used as a food additive, usually for flavor or as a preservative. Sodium citrate is employed as a flavoring agent in certain varieties of club soda. It is common as an ingredient in bratwurst, and is also used in commercial ready-to-drink beverages and drink mixes, contributing a tart flavor. It is found in gelatin mix, ice cream, yogurt, jams, sweets, milk powder, processed cheeses, carbonated beverages, and wine, amongst others.
Sodium citrate can be used as an emulsifier when making cheese. It allows the cheese to melt without becoming greasy.
As a conjugate base of a weak acid, citrate can perform as a buffering agent or acidity regulator, resisting changes in pH. It is used to control acidity in some substances, such as gelatin desserts. It can be found in the milk minicontainers used with coffee machines. The compound is the product of antacids, when they are dissolved in water. The pH of a solution of 5 g/100 ml water at 25°C is 7.5 – 9.0.
It continues to be used today in blood-collection tubes and for the preservation of blood in blood banks. The citrate ion chelates calcium ions in the blood by forming calcium citrate complexes, disrupting the blood clotting mechanism. Recently, trisodium citrate has also been used as a locking agent in vascath and haemodialysis lines instead of heparin due to its lower risk of systemic anticoagulation.
Sodium citrate is used to relieve discomfort in urinary-tract infections, such as cystitis, to reduce the acidosis seen in distal renal tubular acidosis, and can also be used as an osmotic laxative. It is a major component of the WHO oral rehydration solution.
It is used as an antacid, especially prior to anaesthesia, for caesarian section procedures to reduce the risks associated with the aspiration of gastric contents.
Sodium citrate is a particularly effective agent for removal of carbonate scale from boilers without removing them from operation and for cleaning automobile radiators.
|Appearance||Colourless Crystals Or White, Crystalline Powder|
|Solubility (As per Ph. Eur./USP/IP)||Freely soluble in water|
|Heavy Metals||Max. 0.001 %|
|Assay (On Anhydrous Basis)||99 - 100.5% Of C6H5Na3О7|