|Preferred IUPAC name
2,2′,2″-Nitrilotriacetic acid
|Systematic IUPAC name
|Jmol 3D model||Interactive image
|Molar mass||191.14 |
|Melting point||246 °C (475 °F; 519 K)|
|Insoluble. <0.01 g/100 mL at 23℃ |
Std enthalpy of
|−1.3130–−1.3108 MJ mol−1|
|GHS signal word||WARNING|
|H302, H319, H351|
EU classification (DSD)
|R-phrases||R22, R36, R40|
|S-phrases||S26, S36/37/39, S45|
|Flash point||100 °C (212 °F; 373 K)|
|Lethal dose or concentration (LD, LC):|
LD50 (median dose)
|1.1 g kg−1 (oral, rat)|
Related alkanoic acids
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
|what is ?)(|
Nitrilotriacetic acid (NTA) is the aminopolycarboxylic acid with the formula N(CH2CO2H)3. It is a colourless solid that is used as a chelating agent, which forms coordination compounds with metal ions (chelates) such as Ca2+, Cu2+, and Fe3+.
Production and use
Nitrilotriacetic acid is commercially available as the free acid and as the sodium salt. It is produced from ammonia, formaldehyde, and sodium cyanide or hydrogen cyanide. Worldwide capacity is estimated at 100 thousand tonnes per year.
Coordination chemistry and applications
The uses of NTA are similar to that of EDTA, both being chelating agents. In contrast to EDTA, NTA is easily biodegradable and is almost completely removed during wastewater treatment. It is used for water softening and as a replacement to sodium and potassium triphosphate in detergents, and cleansers. NTA is a tripodal tetradentate trianionic ligand. In the laboratory, this compound is used in complexometric titrations. A variant of NTA is used for protein isolation and purification in the His-tag method. The modified NTA is used to immobilize nickel to a solid support. This allows purification of proteins containing a tag consisting of six histidine residues at either terminus.
- Nitrilotriacetic acid
- "Nitrilotriacetic Acid - Compound Summary". PubChem Compound. USA: National Center for Biotechnology Information. 26 March 2005. Identification. Retrieved 13 July 2012.
- ChemBK Chemical Database http://www.chembk.com/en/chem/Nitrilotriacetic%20acid
- NITRILOTRIACETIC ACID AND ITS SALTS, International Agency for Research on Cancer (IARC)
- Charalampos Gousetis, Hans-Joachim Opgenorth (2005), "Nitrilotriacetic Acid", Ullmann's Encyclopedia of Industrial Chemistry, Weinheim: Wiley-VCH, doi:10.1002/14356007.a17_377
- Hart, J. Roger (2005) "Ethylenediaminetetraacetic Acid and Related Chelating Agents" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim. doi:10.1002/14356007.a10_095
- B. L. Barnett, V. A. Uchtman "Structural investigations of calcium-binding molecules. 4. Calcium binding to aminocarboxylates. Crystal structures of Ca(CaEDTA).7H2O and Na(CaNTA)" Inorg. Chem., 1979, volume 18, pp 2674–2678. doi:10.1021/ic50200a007