Information About

Edta




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EDTA is the Chemical Compound '''ethylenediaminetetraacetic acid''', otherwise known as '''edetate''', '''versene''', or '''diaminoethanetetraacetic acid disodium salt'''. EDTA is a Chelating Agent , forming Coordination Compound s with most monovalent, divalent, trivalent and tetravalent Metal Ion s, such as Silver (Ag+), Calcium (Ca2+), Copper (Cu2+), Iron (Fe3+) or Zirconium (Zr4+). EDTA contains 4 Carboxylic Acid and 2 tertiary Amine groups that can participate in acid-base reactions. EDTA forms especially strong complexes with Ca, Cu, Fe(III), and Co(III).

EDTA has a molecular mass of 292.28 g/mol. Its CAS Number is and its SMILES structure is .


USES


Annual consumption of EDTA is about 35,000 tons in 1999 in Europe and 50,000 tons in the US. The most important uses are:

  • Industrial cleaning: complexation of Ca and Mg ions, binding of Heavy Metal s.

  • Detergent s: complexation of Ca and Mg (reduction of water hardness).

  • Photography : use of Fe(III)EDTA as oxidizing agent.

  • Pulp And Paper industry: complexation of heavy metals during chlorine-free bleaching, stabilization of hydrogen peroxide.

  • Textile industry: complexation of heavy metals, bleach stabilizer.

  • Agrochemical s: Fe, Zn and Cu fertilizer, especially in calcareous soils.

  • Hydroponics : iron-EDTA is used to prevent the iron from precipitating out of nutrient solutions.


Less important uses of EDTA are:


In laboratory science, EDTA is also used for:



ENVIRONMENTAL BEHAVIOR


Widespread use of EDTA and its slow removal under many environmental conditions has led to its status as the most abundant Anthropogenic compound in many European surface waters. River concentrations in Europe are reported as 10-100 μg/L, and lake concentrations are in the 1-10 μg/L range. EDTA concentrations in U.S. groundwater receiving wastewater effluent discharge have been reported at 1-72 μg/L, and EDTA was found to be an effective tracer for effluent, with higher concentrations of EDTA corresponding to a greater percentage of reclaimed water in drinking water production wells.

EDTA is not degraded or removed during conventional Wastewater Treatment . However, an adjustment of PH and sludge residence time can result in almost complete mineralization of EDTA. A variety of Microorganism s have been isolated from water, soils, sediments and sludges that are able to completely mineralize EDTA as a sole source of carbon, nitrogen and energy.

Recalcitrant chelating agents such as EDTA are an environmental concern predominantly because of their persistence and strong metal chelating properties. The presence of chelating agents in high concentrations in wastewaters and surface waters has the potential to remobilize heavy metals from river sediments and treated sludges, although low and environmentally relevant concentrations seem to have only a very minor influence on metal solubility. Elevated concentrations of chelating agents enhance the transport of metals (e.g. Zn, Cd, Ni, Cr, Cu, Pb, and Fe) in soils, and enhance the undesired transport of radioactive metals away from disposal sites. Low concentrations of chelating agents may either stimulate or decrease Plankton or Algae growth, while high concentrations always inhibit activity. Chelating agents are nontoxic to many forms of life on Acute exposure; the effects of longer-term low-level exposure are unknown. EDTA at elevated concentrations is toxic to bacteria due to chelation of metals in the Outer Membrane . EDTA ingestion at high concentrations by mammals changes excretion of metals and can affect Cell Membrane permeability.


TRIVIA


  • EDTA played a central role in the O.J. Simpson trial when one of the blood samples collected from O.J. Estate was found to contain traces of the compound. This was used by the defense to indicate that the sample had been planted from one of the vials collected during the investigation. Prosecution claimed EDTA might have appeared in the sample as a result of eating McDonald's foods (either through bloodstream or, more likely, via contamination of blood flowing over the hand used in grabbing the food)

  • "Ethylenediaminetetraacetates" is the longest hypothetically legal Scrabble word (hypothetical because it exceeds 15 letters, the width of a Scrabble board) in North American play

  • EDTA plays an important part in the 1998 Vampire film " Blade ", as it reacts violenty with vampire blood. This property is used to great effect by the eponymous hero.



SEE ALSO



EXTERNAL LINKS



Commercial producers:
Akzo Nobel
Dissolvine Akzo Nobel trade name