Trisodium citrate

Trisodium citrate has the chemical formula of Na3C6H5O7. Sodium citrate dihydrate is the dihydrate of trisodium citrate. It has a role as an anticoagulant. It contains a sodium citrate. 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. It is mildly basic and can be used along with citric acid to make biologically compatible buffers.

Properties

Chemical formula	Na3C6H5O7
Molar mass	258.06 g/mol (anhydrous), 294.10 g/mol (dihydrate)
Appearance	White crystalline powder
Density	1.7 g/cm3
Melting point	> 300 °C (572 °F; 573 K) (hydrates lose water ca. 150 °C)
Boiling point	Decomposes
Solubility in water	Pentahydrate form: 92 g/100 g H2O (25 °C)
chemical structure

 

How Sodium citrate Is Made?

Sodium citrate production occurs by neutralizing citric acid with sodium hydroxide. Citric acid may be produced from fruits or other foods, through yeast fermentation, and by solvent extraction. Most large-scale production occurs by fermenting molasses or other sugar stocks with Aspergillus Niger. The liquid is separated by filtration, and the citric acid is separated by precipitation. Sodium citrate is usually offered commercially as the white, crystalline trisodium citrate dihydrate.

 

Applications

Sodium citrate is often used as a pH adjuster and water softener. It is common in liquid laundry detergent, though it is also often used in food and medical products. In food, it helps control the acidity of ice cream, candy, jelly, and gelatin desserts. Sodium citrate is also in dozens of personal care products, such as shampoo, conditioner, sunscreen, facial moisturizer, makeup, baby wipes, soap, and other product

Sodium salts of citric acid that are used as buffers and food preservatives. They are used medically as anticoagulants in stored blood, and for urine alkalization in the prevention of KIDNEY STONES.

Foods

Citrates are used in the food and beverage industry for their buffering properties, pH control and flavor. Citric acid is the most commonly used acidulant in the industry. As a food additive or food grade product, citric acid is used as a flavoring and preservative. Sodium Citrate, or Trisodium Citrate, is used as an antioxidant in food as well as to improve the effects of other antioxidants. Sodium Citrate can also be used as an acidity regulator and sequestrant. Potassium Citrate acts a buffering agent to adjust the pH when added to water to form buffer solutions.

 

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 ,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.

Buffer

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.

Medical uses

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.

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.

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 and for cleaning automobile radiators.

Citric acid and sodium citrate side effects

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Stop using this medication and call your doctor at once if you have any of these serious side effects:

• swelling, tingling, or numbnessin your hands or feet;
• muscle twitching or pain, leg painor cramps;
• unusual weakness, rapid and shallow breathing, fast or slow heart rate, dizziness, confusion, or mood changes;
• feeling restless, nervous, or irritable;
• black, bloody, or tarry stools;
• severe or ongoing diarrhea; or
• seizure (convulsions).

Less serious side effects may include:

• nausea, or vomiting, stomach pain;
• mild or occasional diarrhea; or
• mild stomach pain.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.