Trisodium Ethylenediamine Disuccinate
[CAS# 178949-82-1]

Identification

• Classification: Flavors and spices >> Synthetic spice >> Carboxylic acid and ester perfume >> Aliphatic carboxylate
• Name: Trisodium Ethylenediamine Disuccinate
• Synonyms: Sodium (S)-2-((2-(((S)-1-carboxy-2-carboxylatoethyl)amino)ethyl)amino)succinate
• Molecular Formula: C₁₀H₁₃N₂Na₃O₈
• Molecular Weight: 358.19
• CAS Registry Number: 178949-82-1
• EC Number: 416-530-4
• SMILES: C(CN[C@@H](CC(=O)[O-])C(=O)[O-])N[C@@H](CC(=O)[O-])C(=O)O.[Na+].[Na+].[Na+]

Safety Data

• Hazard Symbols: GHS07 Warning
• Hazard Statements: H302-H315-H319-H335
• Precautionary Statements: P261-P280-P301+P312-P302+P352-P305+P351+P338

Discovory and Applicatios

Trisodium ethylenediamine disuccinate, commonly abbreviated as Na₃-EDDS, is a water-soluble, biodegradable chelating agent derived from ethylenediamine and succinic acid. It is the trisodium salt of (S,S)-ethylenediamine-N,N'-disuccinic acid, a compound that contains two succinate arms attached to the nitrogen atoms of the ethylenediamine core. The molecule features multiple carboxylate groups and nitrogen atoms that can form stable coordination complexes with metal ions.

EDDS was first synthesized and studied in the 1980s as an alternative to conventional chelating agents like EDTA (ethylenediaminetetraacetic acid). While EDTA is effective in binding metal ions, it is not readily biodegradable and tends to persist in the environment. In contrast, Na₃-EDDS, particularly in its (S,S)-enantiomeric form, degrades more rapidly in soil and aquatic systems, making it more environmentally acceptable.

The primary function of trisodium ethylenediamine disuccinate is to sequester metal ions by forming stable, water-soluble complexes. It is widely used in industrial and household applications for water softening, scale inhibition, and metal ion removal. In detergents and cleaning agents, Na₃-EDDS binds calcium (Ca²⁺), magnesium (Mg²⁺), iron (Fe³⁺), and other metal ions to prevent them from interfering with surfactant action.

In agriculture, Na₃-EDDS serves as a micronutrient carrier, enhancing the availability of essential trace metals like iron and zinc to plants, especially in alkaline soils where these metals are otherwise insoluble. The chelated forms of metal ions are more readily absorbed by plant roots, improving nutrient uptake efficiency.

In environmental remediation, particularly in soil washing and groundwater treatment, Na₃-EDDS has been used to mobilize and extract heavy metals such as lead (Pb), cadmium (Cd), and copper (Cu) from contaminated sites. Its high metal-binding affinity and biodegradability make it an attractive option for reducing metal toxicity without introducing persistent pollutants.

The compound has also been explored in electrochemical applications and dye formulations, where metal control is critical. In cosmetics and personal care products, it can function as a stabilizer by preventing metal-induced degradation of active ingredients.

The biodegradability of Na₃-EDDS is a significant advantage. The (S,S)-isomer is particularly susceptible to microbial degradation, with half-lives in the range of hours to days in activated sludge and natural environments. Its breakdown products are typically non-toxic and further metabolized by environmental microorganisms. In contrast, the racemic and (R,R)-isomers degrade more slowly, and their use is less favored in eco-sensitive formulations.

Trisodium ethylenediamine disuccinate is typically produced via chemical synthesis starting with ethylenediamine and maleic or fumaric acid derivatives, followed by neutralization with sodium hydroxide. The process can yield a mixture of stereoisomers, although enantioselective synthesis routes exist to isolate the (S,S)-form for environmentally responsible applications.

In summary, trisodium ethylenediamine disuccinate is a biodegradable, metal-chelating agent used in a wide range of applications including detergents, agriculture, environmental remediation, and water treatment. Its effectiveness in binding metal ions and its favorable ecological profile make it a valuable alternative to non-degradable chelators like EDTA.