EDTA

What is EDTA?

Molecular Formula (EDTA); C₁₀H₁₆N₂O₈

Molecular Weight; 292.24 g/mol

Chemical Name; Ethylenediamine Tetraacetic Acid

CAS Number; 60-00-4

It is a type of polyamino carboxylic acid. It has more than one -COOH group in its structure. Therefore, it belongs to the polycarboxylic acid group. Since it has an -NH2 group, it takes the amino prefix. Thus, it is classified as a polyamino carboxylic acid. EDTA is the abbreviation for ethylenediaminetetraacetic acid. It is a colorless, crystalline solid.

It is designated as molecular biology grade and is very suitable for molecular biology applications.

It has a very high affinity for certain metal ions. With this property, it can chelate very well. As an anticoagulant agent, Ethylenediaminetetraacetic acid is the chemical with the best properties for this purpose.

Other Names for EDTA are as Follows;

• Ethylenediamine Tetraacetic Acid
• Chelating Agent
• Sequestering Agent
• 60-00-4
• Na2
• Na4

What are its Physical and Chemical Properties?

Melting point is 237 °C.

Boiling point is 100 °C.

Density is 0.86 g/cm³.

Storage temperature is 2-8 °C.

EDTA solubility is 100 mg/mL in 3M NaOH solution. However, it is soluble in water at 0.5 g/L (25 °C). This means it is slightly soluble in water.

In appearance, it is a crystalline solid. It is almost white in color.

It is a stable chemical under normal conditions. It is incompatible with copper, copper alloys, nickel, aluminum, strong oxidizing agents, and strong bases.

How is it Produced?

Today, it is synthesized for industrial purposes by reacting ethylenediamine with formaldehyde and a cyanide source such as HCN or NaCN. First, the sodium salt of EDTA is formed, which can then be acidified.

To acidify this sodium salt, hydrochloric acid or sulfuric acid is added.

One-step and two-step synthesis methods are used in EDTA production. In the two-step production process, a very high purity of this chemical is achieved.

In the one-step production process of Ethylenediamine Tetraacetic Acid, separation is not necessary. Therefore, it requires less equipment and lower installation costs.

In the two-step production process of Ethylenediamine Tetraacetic Acid, the EDTA salt is contaminated with NTA salt.

What are its Effects on Human Health?

In case of skin contact, it causes severe skin irritation. The most serious injuries occur in case of eye contact.

If EDTA comes into contact with any part of the body, it should be washed with water for several minutes. If this does not resolve the issue, medical attention should be sought.

How is it Stored?

As a 0.5 M stock solution at pH 8.5, EDTA can be stored stably for months at a temperature of 4 °C.

It is stored in polyethylene, i.e., plastic containers, instead of glass bottles. The reason is that Ethylenediaminetetraacetic acid in a glass bottle can react with metal ions present in the glass structure over time. However, since plastic containers do not contain metal ions, it can be stored for a longer period in them.

What are its Areas of Use?

• Potassium and sodium salts of EDTA (Ethylenediamine Tetraacetic Acid) are widely used in routine hematology (blood science) assays because they do not damage the cellular components of blood.
• It is used as a chelating agent in cleaning compositions containing magnesium.
• It is one of the chemicals used in the production of carpet shampoo.
• Due to its ability to form stable complexes with most metal ions, EDTA is used in the treatment of lead and heavy metal poisoning in farm animals.
• It is used as a component in household detergents, cosmetic products, pharmaceuticals, and food items.
• Its main function is to interact with metal ions to form complex structures.
• In the aviation industry, cleaning agents are used in container pipes and nozzles to prevent the precipitation of heavy metals that can cause sedimentation and scaling. EDTA is used in the manufacture of these cleaning agents.
• In alkaline degreasing baths, it is used to stabilize phosphates and prevent the flocculation of calcium soap.
• This application with EDTA intensifies the cleaning effect while preventing damage to metal surfaces.
• It is used in the production of milk and beverages. In the dairy industry, it is used to prevent the oxidation of metal ions, because metal ions cause the degradation of dairy products through oxidative decomposition.
• In the photochemicals industry, processes involving the combination of oxidation and fixing of metallic silver (removing silver ions by complexing them) are carried out by applying EDTA before bleaching.
• It is used as a complexing agent and as a tissue preservative in the production of chelated fertilizers.

What are Other Areas of Use?

• In the textile industry, it is used in textile coatings for cross-linking cellulose molecules (to produce easy-care fabrics), to support oxidative bleaching processes, and to prevent potential catalytic damage to fibers.
• In the paper industry, bleaching agents are used to remove residual lignin from cellulose fibers and increase brightness. If the bleaching agent, Hydrogen Peroxide, is used, heavy metals like manganese can decompose the peroxide. The reason for using Ethylenediaminetetraacetic acid is to form a chelated structure, because it does not stick to the paper like manganese, and all of the EDTA is subsequently discharged as waste into the sewer.
• In the metal plating industry, it is used for copper plating by precipitating copper complex compounds onto a board via catalytic reduction. The production of printed circuit boards is achieved with the help of EDTA in this application.
• It is used in water treatment systems to prevent the formation of calcium and magnesium scale. In water treatment systems, it is used as an additive in the boilers of the system's feed water to prevent and clean internal deposits.
• It is used in the production of Styrene Butadiene Elastomer by emulsion polymerization. Its purpose here is to act as a sequestration agent for the Fe(II)/Fe(III) ions in the initiator system.
• It is used as an effective cleaning agent on oil production platforms. It must be added continuously at specific dosages.
• EDTA is used to remove sulfur fumes in coal power plants and waste incineration facilities. For the catalytic removal of hydrogen sulfide, it has an iron-chelating property when used with 70% sorbitol and sodium hydroxide.
• It is used in soaps to prevent color loss and mold formation, thereby enhancing the soap's cleaning effect.
• In food, cosmetic, and pharmaceutical applications, Potassium Sorbate and Sorbic Acid can be used as preservatives. When Potassium Sorbate is used, color degradation may occur. To prevent this, EDTA is used as a complexing agent.
• It is used as a corrosion inhibitor with Hydroxylammonium Sulfate (Hydroxylamine Sulfate) in crystallization units made of stainless steel. It is an important component for solving such corrosion problems.
• It is used as an activator or auxiliary agent in the production of roll-on deodorants.
• It is the chelating agent used for softening the water in the production of Upholstery Cleaning Chemicals.
• It is used for chelating metal ions present in the production of solvent-based industrial surface cleaning detergents.

What Factors Affect EDTA Prices?

The biggest factor affecting the price of EDTA stems from the prices of the raw materials used in its production.

The price of this chemical also depends on the density and specifications of the produced EDTA.

As the concentration increases, the prices increase because the production cost is high.

The price increases as the application areas of EDTA expand.

If a new major manufacturer starts producing EDTA, the price will temporarily decrease but will return to an appropriate level in a short time.