Potassium citrate
[CAS# 866-84-2]

Identification

• Classification: API >> Water, electrolyte and acid-base balance regulator >> Acid-base balance regulator
• Name: Potassium citrate
• Synonyms: Tripotassium citrate; 2-Hydroxy-1,2,3-propanetricarboxylic acid tripotassium salt
• Molecular Formula: C₆H₅K₃O₇
• Molecular Weight: 306.37
• CAS Registry Number: 866-84-2
• EC Number: 212-755-5
• SMILES: C(C(=O)[O-])C(CC(=O)[O-])(C(=O)[O-])O.[K+].[K+].[K+]

Properties

• Solubility: 148% w/w (water 20 ºC)
• Density: 1.98 g/mL (20 ºC)
• Melting point: 230 ºC (decomp.)

Safety Data

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Specific target organ toxicity - single exposure	STOT SE	3	H335
Eye irritation	Eye Irrit.	2	H319
Skin irritation	Skin Irrit.	2	H315
Skin corrosion	Skin Corr.	1A	H314
Acute toxicity	Acute Tox.	4	H302

Discovory and Applicatios

Potassium citrate, with the chemical formula K3C6H5O7, is the potassium salt of citric acid. Its history is tied to citric acid, which was first isolated from lemon juice in 1784 by Swedish chemist Carl Wilhelm Scheele. Scheele's work laid the foundation for the discovery of citrates, including potassium citrate. Potassium citrate is usually produced by neutralizing citric acid with potassium hydroxide or carbonate. The reaction produces a colorless, odorless, slightly salty crystalline compound. Its solubility in water and ability to buffer pH make it a versatile substance in a variety of applications.

Potassium citrate is an alkalizing agent. After ingestion, it is metabolized to bicarbonate, which helps neutralize acidity in the body. This process is essential for diseases where controlling acid balance is key, such as treating kidney stones and metabolic acidosis. Its ability to keep pH balanced makes it important in both medical and nutritional settings.

Potassium citrate is most commonly used in the medical field to prevent and treat kidney stones. Its alkalinizing effect helps reduce the formation of uric acid and calcium oxalate stones by increasing the pH of the urine, making it less acidic. This change in urine composition prevents the crystallization process that leads to stone formation.

People with renal tubular acidosis or cystinuria also benefit from potassium citrate because it helps maintain a more alkaline urine pH, reducing the risk of stones and helping to manage these conditions. In addition, it can be used to treat hypokalemia (low potassium levels) and provide potassium supplementation when dietary intake is inadequate.

In the food industry, potassium citrate is used as an acidity regulator and stabilizer. Its ability to maintain pH is essential for products where acidity can affect flavor, texture, or shelf life. For example, it is often used in processed cheeses, beverages, and desserts to ensure consistency and prevent spoilage.

Potassium citrate can also enhance the buffering capacity of foods, helping to stabilize emulsions and improve the quality of sauces and dressings. In beverages, it can balance flavors by controlling acidity, making it a valuable ingredient in soft drinks and energy drinks.

In addition to its primary applications, potassium citrate is used in a variety of other industries. It functions in medicine as an ingredient in oral rehydration salts and effervescent tablets. In cosmetics, its buffering properties can be used in formulations to maintain the stability and efficacy of skin care products.

In agriculture, potassium citrate can be used as a fertilizer ingredient to provide plants with essential potassium and help balance soil pH. This diverse application highlights its versatility and importance in different fields.