Sodium Citrate

Sodium citrate is a white, crystalline powder that is highly soluble in water. It is a sodium salt of citric acid, which is a weak organic acid found in citrus fruits. Sodium citrate is commonly used as a food additive, a preservative, and a chelating agent.

Sodium Citrate Structure

Sodium citrate is a white, crystalline powder that is highly soluble in water. It is an organic compound with the chemical formula $\ce{Na3C6H5O7}$. The structure of sodium citrate consists of a central carbon atom surrounded by three carboxyl groups $\ce{(-COO-)}$ and three hydroxyl groups $\ce{(-OH)}$. The carboxyl groups are ionized in water, giving sodium citrate its characteristic sour taste.

Molecular Formula

The molecular formula of sodium citrate is $\ce{Na3C6H5O7}$. This formula indicates that each molecule of sodium citrate contains three sodium atoms, six carbon atoms, five hydrogen atoms, and seven oxygen atoms.

Structural Formula

The structural formula of sodium citrate is:

$O=C(O-)C(O-)C(O-)C(OH)(OH)CH2COO-$ | $Na^+$ | $Na^+$ | $Na^+$

In this formula, the carbon atoms are represented by the letter C, the hydrogen atoms are represented by the letter H, the oxygen atoms are represented by the letter O, and the sodium atoms are represented by the letter Na. The bonds between the atoms are represented by lines.

Functional Groups

The functional groups present in sodium citrate include:

• Carboxyl group $\ce{(-COO-)}$: The carboxyl group is a functional group that consists of a carbon atom double-bonded to an oxygen atom and single-bonded to a hydroxyl group.
• Hydroxyl group $\ce{(-OH)}$: The hydroxyl group is a functional group that consists of an oxygen atom single-bonded to a hydrogen atom.

Sodium citrate is a versatile compound with a variety of uses. Its unique structure and properties make it a valuable ingredient in many different products.

Sodium Citrate Formula

Sodium citrate is a chemical compound with the formula $\ce{Na3C6H5O7}$. It is a white, crystalline powder that is highly soluble in water. Sodium citrate is used as a food additive, a preservative, and a chelating agent.

Chemical Formula

The chemical formula for sodium citrate is $\ce{Na3C6H5O7}$. This formula indicates that sodium citrate is composed of three sodium atoms, six carbon atoms, five hydrogen atoms, and seven oxygen atoms.

Structure

Sodium citrate has a molecular structure that consists of a central carbon atom surrounded by four oxygen atoms. The carbon atom is also bonded to three hydrogen atoms and one sodium atom. The remaining two sodium atoms are bonded to the oxygen atoms.

Uses

Sodium citrate is used in a variety of applications, including:

• Food additive: Sodium citrate is used as a food additive to enhance flavor, preserve food, and prevent spoilage. It is commonly used in processed cheese, canned vegetables, and soft drinks.
• Preservative: Sodium citrate is used as a preservative to prevent the growth of bacteria and mold. It is commonly used in cosmetics, pharmaceuticals, and food products.
• Chelating agent: Sodium citrate is used as a chelating agent to bind to metal ions and prevent them from reacting with other substances. It is commonly used in water treatment, metalworking, and textile manufacturing.

Health Benefits

Sodium citrate has a number of health benefits, including:

• Prevents kidney stones: Sodium citrate can help to prevent the formation of kidney stones by binding to calcium and preventing it from crystallizing.
• Treats urinary tract infections: Sodium citrate can help to treat urinary tract infections by making the urine more alkaline and preventing the growth of bacteria.
• Relieves heartburn: Sodium citrate can help to relieve heartburn by neutralizing stomach acid.

Sodium citrate is a versatile compound with a wide range of applications. It is used as a food additive, a preservative, and a chelating agent. Sodium citrate also has a number of health benefits, including preventing kidney stones, treating urinary tract infections, and relieving heartburn.

Functions of Sodium Citrate

Sodium citrate is a versatile compound with various functions in different industries. Here are some of its key functions:

Food Industry:

• Preservative: Sodium citrate acts as a preservative in food products by inhibiting the growth of bacteria and molds. It is commonly used in canned vegetables, fruits, and meat products.

• Flavor Enhancer: Sodium citrate enhances the flavor of certain foods, particularly acidic ones. It is often added to beverages, jams, jellies, and desserts to balance and improve their taste.

• Emulsifier: Sodium citrate acts as an emulsifier, helping to blend ingredients that would otherwise not mix well. It is used in salad dressings, mayonnaise, and other sauces to create a smooth and stable emulsion.

• Stabilizer: Sodium citrate stabilizes food products by preventing the separation of ingredients. It is commonly used in ice cream, frozen desserts, and whipped cream to maintain their texture and consistency.

Pharmaceutical Industry:

• Anticoagulant: Sodium citrate is used as an anticoagulant in blood collection tubes to prevent blood from clotting during medical tests and procedures.

• Buffering Agent: Sodium citrate acts as a buffering agent, maintaining a stable pH level in pharmaceutical formulations. It is used in intravenous fluids, eye drops, and other medicinal products.

• Laxative: Sodium citrate is sometimes used as a laxative to relieve constipation. It works by drawing water into the intestines, stimulating bowel movements.

Industrial Applications:

• Water Softener: Sodium citrate is used as a water softener in industrial boilers and cooling systems. It prevents the formation of scale and deposits by binding with calcium and magnesium ions.

• Detergent Builder: Sodium citrate is added to detergents and cleaning products to enhance their cleaning power. It helps to break down dirt and grime, making it easier to remove.

• Metal Finishing: Sodium citrate is used in metal finishing processes to remove tarnish and polish metal surfaces.

• Textile Industry: Sodium citrate is employed in the textile industry as a dyeing assistant and fabric softener.

Other Uses:

• Culinary Arts: Sodium citrate is used in molecular gastronomy to create unique textures and flavors in dishes.

• Cosmetics: Sodium citrate is found in some cosmetic products, such as bath salts and facial cleansers.

• Photography: Sodium citrate is used as a toning agent in photography to enhance the appearance of prints.

Sodium citrate’s versatility and wide range of applications make it a valuable compound in various industries. Its properties as a preservative, flavor enhancer, emulsifier, stabilizer, anticoagulant, buffering agent, laxative, water softener, detergent builder, metal finishing agent, textile assistant, and culinary ingredient contribute to its diverse uses.

Sodium Citrate Properties

Sodium citrate is a white, crystalline powder that is highly soluble in water. It has a slightly salty taste and is commonly used as a food additive, preservative, and anticoagulant.

Chemical Properties

• Chemical formula: $\ce{C6H5Na3O7}$
• Molar mass: 258.07 g/mol
• Melting point: 150 °C (302 °F)
• Boiling point: 330 °C (626 °F)
• Density: 1.85 g/cm³
• Solubility in water: 78 g/100 mL (25 °C)

Physical Properties

• Appearance: White, crystalline powder
• Odor: Odorless
• Taste: Slightly salty
• pH: 7.5-8.5 (1% solution)

Functional Properties

• Acidity regulator: Sodium citrate can be used to adjust the pH of foods and beverages.
• Anticoagulant: Sodium citrate can prevent blood from clotting by binding to calcium ions.
• Buffer: Sodium citrate can help to maintain a stable pH in solutions.
• Chelating agent: Sodium citrate can bind to metal ions, such as iron and copper, to prevent them from reacting with other substances.
• Emulsifier: Sodium citrate can help to disperse oil and water in emulsions.
• Flavor enhancer: Sodium citrate can enhance the flavor of foods and beverages.
• Preservative: Sodium citrate can inhibit the growth of bacteria and fungi.
• Sequestrant: Sodium citrate can bind to metal ions to prevent them from reacting with other substances.
• Stabilizer: Sodium citrate can help to stabilize emulsions and foams.
• Thickener: Sodium citrate can help to thicken sauces and gravies.

Sodium citrate is a versatile compound with a wide range of properties and applications. It is commonly used as a food additive, preservative, and anticoagulant. Sodium citrate is generally recognized as safe (GRAS) by the U.S. Food and Drug Administration (FDA).

Difference Between EDTA and Sodium Citrate

EDTA (ethylenediaminetetraacetic acid) and sodium citrate are two common anticoagulants used in blood collection and processing. While both substances prevent blood from clotting, they have different mechanisms of action and are used for different purposes.

Mechanism of Action

EDTA: EDTA works by chelating calcium ions, which are essential for the activation of the blood clotting cascade. By binding to calcium, EDTA prevents the formation of fibrin, the protein that forms blood clots.

Sodium Citrate: Sodium citrate works by binding to calcium ions and also by inhibiting the action of thrombin, an enzyme that plays a crucial role in the clotting process.

Uses

EDTA: EDTA is commonly used in the collection of blood samples for complete blood counts (CBCs) and other hematology tests. It is also used in the preservation of organs and tissues for transplantation.

Sodium Citrate: Sodium citrate is primarily used in the collection of blood samples for coagulation studies, such as prothrombin time (PT) and activated partial thromboplastin time (APTT). It is also used in the preparation of platelet-rich plasma (PRP) and in the storage of whole blood for transfusions.

Advantages and Disadvantages

EDTA:

• Advantages:
• EDTA is a powerful anticoagulant that effectively prevents blood from clotting.
• It does not interfere with most hematology tests.
• Disadvantages:
• EDTA can cause platelet clumping, which can affect platelet counts and other platelet-related tests.
• It can also bind to other metal ions, such as magnesium and zinc, which can interfere with certain tests.

Sodium Citrate:

• Advantages:
• Sodium citrate does not cause platelet clumping and is therefore preferred for coagulation studies.
• It is also less likely to interfere with other blood tests.
• Disadvantages:
• Sodium citrate can alter the pH of the blood sample, which can affect certain tests.
• It can also lead to the formation of fibrin clots if the blood sample is not processed promptly.

EDTA and sodium citrate are both effective anticoagulants, but they have different mechanisms of action and are used for different purposes. The choice of anticoagulant depends on the specific blood test or procedure being performed.

Sodium Citrate FAQs

What is sodium citrate?

Sodium citrate is a white, crystalline powder that is soluble in water. It is a salt of citric acid, which is a naturally occurring acid found in citrus fruits. Sodium citrate is used as a food additive, a preservative, and a medicine.

What are the uses of sodium citrate?

Sodium citrate has a variety of uses, including:

• Food additive: Sodium citrate is used as a flavor enhancer, a pH adjuster, and a stabilizer in foods such as processed cheese, canned vegetables, and soft drinks.
• Preservative: Sodium citrate can be used to prevent the growth of bacteria and mold in foods.
• Medicine: Sodium citrate is used to treat a variety of medical conditions, including:
• Kidney stones
• Urinary tract infections
• Muscle spasms
• Heartburn
• Indigestion

Is sodium citrate safe?

Sodium citrate is generally considered safe when used in moderation. However, some people may experience side effects such as nausea, vomiting, and diarrhea. Sodium citrate can also interact with certain medications, so it is important to talk to your doctor before taking it if you are taking any other medications.

How much sodium citrate should I take?

The amount of sodium citrate you should take depends on the reason you are taking it. For food additive purposes, the typical amount is 0.5-1% of the total weight of the food. For preservative purposes, the typical amount is 0.1-0.2% of the total weight of the food. For medical purposes, the typical dose is 300-600 mg per day.

Where can I buy sodium citrate?

Sodium citrate can be purchased online or at most grocery stores. It is typically sold in the spice section or near the baking supplies.

Conclusion

Sodium citrate is a versatile substance that has a variety of uses. It is generally considered safe when used in moderation, but it is important to talk to your doctor before taking it if you are taking any other medications.