Sodium N-(2-hydroxylethyl)ethylenediamine-N,N',N'-triacetate
[CAS# 139-89-9]

Identification

• Classification: Organic raw materials >> Carboxylic compounds and derivatives
• Name: Sodium N-(2-hydroxylethyl)ethylenediamine-N,N',N'-triacetate
• Synonyms: N-(2-Hydroxyethyl)-N,N',N'-ethylenediaminetriacetic acid trisodium salt; N-(Carboxymethyl)-N'-(2-hydroxyethyl)-N,N'-ethylenediglycine trisodium salt; N-(2-hydroxyethyl)ethylenediaminetriacetate; Trisodium N-(hydroxyethyl)ethylenediaminetriacetate; Trisodium N-hydroxyethylethylenediamine-N,N',N'-triacetate
• Molecular Formula: C₁₀H₁₅N₂O₇.₃Na
• Molecular Weight: 344.21
• CAS Registry Number: 139-89-9
• EC Number: 205-381-9
• SMILES: C(CN(CC(=O)[O-])CC(=O)[O-])N(CCO)CC(=O)[O-].[Na+].[Na+].[Na+]

Properties

• Density: 1.300 g/mL (Expl.)
• Melting point: 288 °C (Expl.)

Safety Data

• Hazard Symbols: GHS07 Warning
• Risk Statements: H315-H319
• Safety Statements: P264-P280-P302+P352+P332+P313+P362+P364-P305+P351+P338+P337+P313

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Serious eye damage	Eye Dam.	1	H318
Skin irritation	Skin Irrit.	2	H315
Acute hazardous to the aquatic environment	Aquatic Acute	1	H400
Chronic hazardous to the aquatic environment	Aquatic Chronic	1	H410
Acute toxicity	Acute Tox.	4	H302
Eye irritation	Eye Irrit.	2	H319
Eye irritation	Eye Irrit.	2B	H320

Discovery and Applications

Sodium N-(2-hydroxyethyl)ethylenediamine-N,N',N'-triacetate (commonly abbreviated as HEDTA-Na) is a chelating agent derived from ethylenediamine. It features a hydroxyethyl group and three acetate groups, which provide excellent metal-binding properties. The discovery of HEDTA-Na emerged from mid-20th-century research aimed at developing versatile ligands for industrial and agricultural applications.

HEDTA-Na is synthesized through the reaction of ethylenediamine with monochloroacetic acid, followed by hydroxyethylation. Its ability to chelate metal ions is attributed to the nitrogen and oxygen donor atoms in its structure, which form stable complexes with a wide range of metal cations. This feature makes it highly effective in applications where control over metal ions is critical.

One of the primary applications of HEDTA-Na is in industrial water treatment. It is used to sequester metal ions such as calcium, magnesium, and iron, preventing scale formation and improving the efficiency of boilers and cooling systems. Its stability under varying pH conditions enhances its utility in such systems.

In agriculture, HEDTA-Na serves as a micronutrient carrier in fertilizers. By forming soluble complexes with essential trace metals like iron, zinc, and manganese, it facilitates their availability to plants, thereby improving crop yield and health. It is particularly beneficial in soils with high alkalinity, where metal ions are typically less bioavailable.

HEDTA-Na is also employed in personal care products and detergents. In cosmetics, it stabilizes formulations by binding trace metals that could otherwise catalyze oxidative degradation. In cleaning products, it enhances performance by preventing metal-induced precipitation of active ingredients.

The discovery and diverse applications of HEDTA-Na underscore its significance as a versatile chelating agent. Its ability to manage metal ions effectively has made it indispensable in multiple industrial, agricultural, and consumer contexts.

References

2003. Aluminum-induced oxidative stress in rat brain: response to combined administration of citric acid and HEDTA. Comparative Biochemistry and Physiology Part C: Toxicology & Pharmacology.
DOI: 10.1016/s1532-0456(02)00269-7

2017. Modifier-free separation of trivalent actinides and lanthanides from fast reactor simulated high-level liquid waste using N,N-di-octyl-2-hydroxyacetamide. Journal of Radioanalytical and Nuclear Chemistry.
DOI: 10.1007/s10967-017-5528-z

2012. Zn-Sn electrodeposition from deep eutectic solvents containing EDTA, HEDTA, and Idranal VII. Journal of Applied Electrochemistry.
DOI: 10.1007/s10800-012-0431-3