Trisodium citrate

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Sodium citrate
Natriumcitrat V1.svg
Trisodium Citrate taken with my iPhone SE in my kitchen.jpg
IUPAC name
Trisodium citrate
Preferred IUPAC name
Trisodium 2-hydroxypropane-1,2,3-tricarboxylate
Other names
Citric acid, trisodium salt
Sodium citrate
3D model (JSmol)
ECHA InfoCard 100.000.614 OOjs UI icon edit-ltr-progressive.svg
E number E331iii (antioxidants, ...)
PubChem CID
RTECS number
  • GE8300000
  • InChI=1S/C6H8O7.3Na/c7-3(8)1-6(13,5(11)12)2-4(9)10;;;/h13H,1-2H2,(H,7,8)(H,9,10)(H,11,12);;;/q;3*+1/p-3 X mark.svgN
  • InChI=1/C6H8O7.3Na/c7-3(8)1-6(13,5(11)12)2-4(9)10;;;/h13H,1-2H2,(H,7,8)(H,9,10)(H,11,12);;;/q;3*+1/p-3
  • C(C(=O)[O-])C(CC(=O)[O-])(C(=O)[O-])O.[Na+].[Na+].[Na+]
Molar mass 258.06 g/mol (anhydrous), 294.10 g/mol (dihydrate)
AppearanceWhite crystalline powder
Density 1.7 g/cm3
Melting point > 300 °C (572 °F; 573 K)(hydrates lose water ca. 150 °C)
Boiling point Decomposes
Pentahydrate form: 92 g/100 g H2O (25 °C) [1]
Occupational safety and health (OHS/OSH):
Main hazards
NFPA 704 (fire diamond)
Lethal dose or concentration (LD, LC):
1548 mg/kg (intraperitoneal, rat) [2]
Safety data sheet (SDS) External MSDS
Related compounds
Related compounds
Monosodium citrate
Disodium citrate
Calcium citrate
Citric acid
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Trisodium citrate has the chemical formula of Na3C6H5O7. It is sometimes referred to simply as "sodium citrate", though sodium citrate can refer to any of the three sodium salts of citric acid. It possesses a saline, mildly tart flavor, and is a mild alkali.




Sodium citrate is chiefly used as a food additive, usually for flavor or as a preservative. Its E number is E331. 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, [3] amongst others.

Sodium citrate can be used as an emulsifying stabilizer when making cheese. It allows the cheese to melt without becoming greasy by stopping the fats from separating.


Speciation diagram for a 10-millimolar solution of citric acid. The violet curve corresponds to the trisodium citrate. Citric acid speciation.svg
Speciation diagram for a 10-millimolar solution of citric acid. The violet curve corresponds to the trisodium citrate.

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, such as Alka-Seltzer, when they are dissolved in water.[ citation needed ] The pH of a solution of 5 g/100 ml water at 25 °C is 7.5 – 9.0. It is added to many commercially packaged dairy products to control the PH impact of the gastrointestinal system of humans, mainly in processed products such as cheese and yogurt.


In 1914, the Belgian doctor Albert Hustin and the Argentine physician and researcher Luis Agote successfully used sodium citrate as an anticoagulant in blood transfusions, with Richard Lewisohn determining its correct concentration in 1915. 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. [4]

In 2003, Ööpik et al. showed the use of sodium citrate (0.5 g/kg body weight) improved running performance over 5 km by 30 seconds. [5]

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.

Boiler descaling

Sodium citrate is a particularly effective agent for removal of carbonate scale from boilers without removing them from operation [6] and for cleaning automobile radiators. [7]

See also

Related Research Articles

Antacid Substance that relieves stomach problems

An antacid is a substance which neutralizes stomach acidity and is used to relieve heartburn, indigestion or an upset stomach. Some antacids have been used in the treatment of constipation and diarrhea. Marketed antacids contain salts of aluminum, calcium, magnesium, or sodium. Some preparations contain a combination of two salts, such as magnesium carbonate and aluminium hydroxide.

Citric acid Weak organic acid

Citric acid is an organic compound with the chemical formula HOC(CO2H)(CH2CO2H)2. It is a colorless weak organic acid. It occurs naturally in citrus fruits. In biochemistry, it is an intermediate in the citric acid cycle, which occurs in the metabolism of all aerobic organisms.

An organic acid is an organic compound with acidic properties. The most common organic acids are the carboxylic acids, whose acidity is associated with their carboxyl group –COOH. Sulfonic acids, containing the group –SO2OH, are relatively stronger acids. Alcohols, with –OH, can act as acids but they are usually very weak. The relative stability of the conjugate base of the acid determines its acidity. Other groups can [also] confer acidity, usually weakly: the thiol group –SH, the enol group, and the phenol group. In biological systems, organic compounds containing these groups are generally referred to as organic acids.

Sodium carbonate Chemical compound

Sodium carbonate, Na2CO3·10H2O, (also known as washing soda, soda ash and soda crystals) is the inorganic compound with the formula Na2CO3 and its various hydrates. All forms are white, odourless, water-soluble salts that yield moderately alkaline solutions in water. Historically, it was extracted from the ashes of plants growing in sodium-rich soils. Because the ashes of these sodium-rich plants were noticeably different from ashes of wood (once used to produce potash), sodium carbonate became known as "soda ash". It is produced in large quantities from sodium chloride and limestone by the Solvay process.

Benedict's reagent is a chemical reagent and complex mixture of sodium carbonate, sodium citrate, and copper(II) sulfate pentahydrate. It is often used in place of Fehling's solution to detect the presence of reducing sugars. The presence of other reducing substances also gives a positive result. Such tests that use this reagent are called the Benedict's tests. A positive test with Benedict's reagent is shown by a color change from clear blue to brick-red with a precipitate.

Calcium citrate Chemical compound

Calcium citrate is the calcium salt of citric acid. It is commonly used as a food additive (E333), usually as a preservative, but sometimes for flavor. In this sense, it is similar to sodium citrate. Calcium citrate is also found in some dietary calcium supplements. Calcium makes up 24.1% of calcium citrate (anhydrous) and 21.1% of calcium citrate (tetrahydrate) by mass. The tetrahydrate occurs in nature as the mineral Earlandite.

Pocari Sweat Sports drink

Pocari Sweat is a Japanese sports drink, manufactured by Otsuka Pharmaceutical. It was launched in 1980, and is mostly well known across Asia and the Middle East; it is also available in East Asia, Southeast Asia, Australia and Mexico.

Pepsi Wild Cherry Cherry-flavored soft drink

Pepsi Wild Cherry is a cherry-flavored cola first introduced in 1988 by PepsiCo as a replacement for Cherry Cola Slice, introduced as part of the line in 1986. Two sugar-free versions are also available, with zero calories, named Diet Pepsi Wild Cherry and Pepsi Zero Sugar Wild Cherry, and a vanilla-flavored version Pepsi Cherry Vanilla is also available. Alongside the beverages, a Lip Balm version is also available. Pepsi Wild Cherry is currently sold in the United States and Canada as a regular, permanent product.

Ringers lactate solution

Ringer's lactate solution (RL), also known as sodium lactate solution and Hartmann's solution, is a mixture of sodium chloride, sodium lactate, potassium chloride, and calcium chloride in water. It is used for replacing fluids and electrolytes in those who have low blood volume or low blood pressure. It may also be used to treat metabolic acidosis and to wash the eye following a chemical burn. It is given by intravenous infusion or applied to the affected area.

Easy Cheese Squirtable canned processed cheese product

Easy Cheese is the trademark for a processed cheese spread product distributed by Mondelēz International. It is also referred to as "spray cheese", "cheese fizz", or simply "cheese in a can", and is similar to "squeeze cheese". Easy Cheese is packaged in a metal can filled with air covered with a plastic cap that reveals a straight, flexible nozzle where the cheese is extruded.

Calcium lactate Chemical compound

Calcium lactate is a white crystalline salt with formula C
, consisting of two lactate anions H
for each calcium cation Ca2+
. It forms several hydrates, the most common being the pentahydrate C

Propel Water

Propel Water is an American brand of flavored bottled water that is advertised for having antioxidants and vitamins. It is a beverage product of Gatorade and is marketed by PepsiCo.

Monosodium citrate Chemical compound

Monosodium citrate, more correctly, sodium dihydrogen citrate (Latin: natrium citricum acidulatum), is an acid salt of citric acid. Disodium citrate and trisodium citrate are also known. It can be prepared by partial neutralisation of an aqueous solution of sodium bicarbonate or carbonate with citric acid.

Disodium citrate Chemical compound

Disodium citrate, more properly, disodium hydrogen citrate, is an acid salt of citric acid with the chemical formula Na2C6H6O7. It is used as an antioxidant in food and to improve the effects of other antioxidants. It is also used as an acidity regulator and sequestrant. Typical products include gelatin, jam, sweets, ice cream, carbonated beverages, milk powder, wine, and processed cheeses.

Sodium lactate Chemical compound

Sodium lactate is the sodium salt of lactic acid, and has a mild saline taste. It is produced by fermentation of a sugar source, such as corn or beets, and then, by neutralizing the resulting lactic acid to create a compound having the formula NaC3H5O3.


Acidulants are chemical compounds that give a tart, sour, or acidic flavor to foods or enhance the perceived sweetness of foods. Acidulants can also function as leavening agents and emulsifiers in some kinds of processed foods. Though acidulants can lower pH they do differ from acidity regulators, which are food additives specifically intended to modify the stability of food or enzymes within it. Typical acidulants are acetic acid and citric acid. Many beverages, such as colas, contain phosphoric acid. Sour candies often are formulated with malic acid. Other acidulants used in food production include: fumaric acid, tartaric acid, lactic acid and gluconic acid.

Cleaning agent Substance used to remove dirt or other contaminants

Cleaning agents or hard-surface cleaners are substances used to remove dirt, including dust, stains, bad smells, and clutter on surfaces. Purposes of cleaning agents include health, beauty, removing offensive odor, and avoiding the spread of dirt and contaminants to oneself and others. Some cleaning agents can kill bacteria and clean at the same time. Others, called degreasers, contain organic solvents to help dissolve oils and fats.

Sodium citrate may refer to any of the sodium salts of citric acid :

Sour cream Fermented dairy product

Sour cream or soured cream is a dairy product obtained by fermenting regular cream with certain kinds of lactic acid bacteria. The bacterial culture, which is introduced either deliberately or naturally, sours and thickens the cream. Its name comes from the production of lactic acid by bacterial fermentation, which is called souring. Crème fraîche is one type of sour cream with a high fat content and less sour taste.


  1. "CRC Handbook of Chemistry and Physics" . Retrieved 22 November 2013.
  2. Chambers, Michael. "ChemIDplus - 68-04-2 - HRXKRNGNAMMEHJ-UHFFFAOYSA-K - Sodium citrate anhydrous - Similar structures search, synonyms, formulas, resource links, and other chemical information".
  3. "Permitted Emulsifying Salt (E331)".
  4. "Locking Solutions for Hemodialysis Catheters" (PDF).
  5. V. Ööpik; I. Saaremets; L. Medijainen; K. Karelson; T. Janson; S. Timpmann (2003). "Effects of sodium citrate ingestion before exercise on endurance performance in well trained college runners". British Journal of Sports Medicine. 37 (6): 485–489. doi:10.1136/bjsm.37.6.485. PMC   1724692 . PMID   14665584.
  6. U.S. Patent 3,095,862
  7. "MSDS" (PDF).