Description
Sodium citrate is the trisodium salt of citric acid, commonly used as a buffering agent, emulsifier, and preservative in a wide range of food, pharmaceutical, and industrial applications. It appears as a white, odorless, crystalline powder that dissolves readily in water. Known for its high alkalinity and excellent chelating properties, sodium citrate helps stabilize pH and prevent metal ion reactions.
In the food industry, it adjusts acidity and enhances flavors in beverages, dairy products, and processed foods. In pharmaceuticals, it functions as an alkalizing agent and anticoagulant. Sodium citrate is also valued in detergents and water treatment formulations for its ability to soften hard water and bind calcium and magnesium ions. It is recognized as safe (GRAS) and approved under the food additive code E331.
Chemical Properties
Chemical Name: Sodium Citrate
Synonyms: Trisodium citrate, Citric acid trisodium salt, E331
Molecular Formula: C₆H₅Na₃O₇
Molecular Weight: 258.06 g/mol
CAS Number: 68-04-2
EC Number: 200-675-3
Appearance: White crystalline powder, granules or liquid
Odor: Odorless
Solubility: Highly soluble in water, insoluble in alcohol
Density: ~1.76 g/cm³
pH (1% solution): 7.5–9.0
Melting Point: ~300°C (decomposes)
Boiling Point: Not applicable
Chelating Ability: High affinity for metal ions (Ca²⁺, Mg²⁺)
Biodegradability: Readily biodegradable
Regulatory Status: Approved as E331 by FDA, EFSA, and other authorities
Applications
Food Industry: pH control, flavor enhancer, emulsifier
Pharmaceuticals: Alkalinizing agent, anticoagulant in blood storage
Detergents & Cleaning Products: Water softener, chelating agent
Cosmetics: Stabilizer and buffering agent
Industrial Uses: Water treatment, electroplating, textile processing
Industries of Use
Food & Beverage:
Sodium citrate adjusts acidity and maintains flavor stability in beverages, dairy products, jams, and sauces. It acts as an emulsifying salt in processed cheeses and helps control crystallization in syrups.
Pharmaceuticals:
Used in effervescent tablets and antacids to regulate pH. It also acts as a blood anticoagulant in medical storage and as a buffering agent in injectable solutions.
Cleaning & Detergents:
Sodium citrate softens hard water and boosts the performance of surfactants in laundry detergents, dishwashing products, and eco-friendly cleaners.
Cosmetics & Toiletries:
Formulators use it to stabilize emulsions and maintain pH in lotions, shampoos, and creams.
Industrial Applications:
In water treatment, it binds hard water ions. In electroplating, it functions as a complexing agent. In textiles, it assists dye fixation and processing.
Storage Conditions
Store in a tightly sealed container in a dry, cool, and ventilated area.
Protect from moisture, acids, and direct sunlight.
Avoid contact with incompatible substances such as strong oxidizers.
Packaging
20 L HDPE drum (aqueous solution)
200 L HDPE barrel (aqueous solution)
Packaging complies with GHS, REACH, and international transport regulations.
Safety & Handling
Use appropriate PPE including gloves and goggles.
Avoid inhalation of dust and contact with eyes or skin.
Store away from food and beverages.
Dispose of waste according to local environmental guidelines.
