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Trioctyl Tertiary Amine

Trioctyl tertiary amine, commonly referred to as TOA, is an organic compound with the chemical formula (C8H17)3N. It is a member of the amine family and is characterized by having three octyl (8-carbon) groups attached to a central nitrogen atom. 

CAS No.: 1116-76-3

Molecular formula: (C8H17)3N

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Structure Diagram of Trioctyl Tertiary Amine



Molecular formula


Molecular structure diagram

Trioctyl Tertiary Amine of Molecular Structure Diagram

Properties: Colorless or light yellow transparent oily liquid. Melting point -34℃, boiling point 315℃. Density (20℃) 0.811 g/mL, refractive index (Nd20) 1.449. Soluble in alcohols and ethers; soluble in nonpolar solvents, slightly soluble in water. It has the smell of ammonia, with alkalinity.

Introduction of Trioctyl Tertiary Amine


TOA finds various uses across different industries. It is commonly employed as an extraction agent in hydrometallurgical processes for the separation and purification of metals. It can selectively extract metal ions from aqueous solutions, facilitating their separation from other components.


Storage and transportation: Stored in a cool and dry place without contact with acidic substances.


Packing: 160 kg/iron drum.

Specifications of Trioctyl Tertiary Amine




Tertiary Amine Content



Primary Amine and Secondary Amine



Total Amine Value

mg KOH/g






Pt-Co Color Number



Colorless or light yellow transparent oily liquid

Function Principle of Trioctyl tertiary amine (TOA)


In metal extraction processes, TOA acts as a phase transfer agent. It forms a complex with metal ions present in the aqueous solution and transfers them to an organic phase. This process is known as solvent extraction or liquid-liquid extraction. The organic phase containing the extracted metal ions can then undergo further processing or separation steps to isolate the desired metal.


TOA's ability to extract metal ions is attributed to the coordination chemistry between the amine group and the metal ions. The nitrogen atom in TOA forms a coordinate bond with the metal ion, effectively separating it from the aqueous phase.


The choice of TOA as an extraction agent depends on the specific metal ions being targeted for extraction. Different amine-based extractants may exhibit varying selectivity towards different metal ions, allowing for the separation and purification of specific metals.


Apart from metal extraction, TOA can also function as a surfactant, providing surface-active properties in certain applications. It can reduce surface tension and stabilize emulsions or dispersions.

Precautions for Trioctyl Tertiary Amine

Is Trioctyl Tertiary Amine Hazardous?

TOA can be hazardous if not handled properly. It is toxic if swallowed, inhaled, or in contact with the skin. It may cause irritation or burns and can be harmful to aquatic life. Proper safety precautions, such as wearing protective clothing and gloves, should be followed when working with TOA.

Are There Any Alternatives to Trioctyl Tertiary Amine?

Depending on the specific application, there may be alternative compounds or methods available. In metal extraction processes, other amine-based extractants or different extraction techniques like solvent extraction or ion exchange may be used. It is recommended to consult with experts or professionals in the field for guidance on suitable alternatives.