EDTA is an amino polycarboxylic acid that can chelate metal ions. It has the formula [CH2N(CH2CO2H)2]2. It helps remove heavy metals from the body. EDTA also preserves blood samples and food products.
| Iupac name | disodium 2,2’,2’‘,2’‘’-(ethane-1,2-diyldiammonio)tetraacetate |
| Molecular formula | C10H14N2Na2O8 |
| CAS number | 139-33-3 |
| Synonyms | (ethylenedinitrilo)tetraacetic acid disodium salt, disodium edetate, disodium EDTA, edetate disodium, EDTA disodium, EDTA disodium salt, ethylenebis (iminodiacetic acid) disoidum salt, N,N’-1,2-ethanediylbis [N-(carboxymethyl)glycine], disodium salt, Na2-EDTA, Na2H2EDTA |
| Inchi | InChI=1S/C10H16N2O8.2Na/c13-7(14)3-11(4-8(15)16)1-2-12(5-9(17)18)6-10(19)20;;/h1-6H2,(H,13,14)(H,15,16)(H,17,18)(H,19,20);;/q;2*+1/p-2 |
EDTA Properties
EDTA Formula
EDTA stands for ethylenediaminetetraacetic acid, which is a synthetic organic compound that can chelate metal ions. The formula of EDTA is C10H16N2O8, which means it has 10 carbon atoms, 16 hydrogen atoms, 2 nitrogen atoms and 8 oxygen atoms in its molecule.
EDTA Molar Mass
The molar mass of disodium edetate is the sum of the atomic masses of all the atoms in its formula. The atomic masses of carbon, hydrogen, nitrogen and oxygen are 12.01 g/mol, 1.01 g/mol, 14.01 g/mol and 16.00 g/mol respectively. Therefore, the molar mass of disodium edetate is (10 x 12.01) + (16 x 1.01) + (2 x 14.01) + (8 x 16.00) = 292.24 g/mol.
EDTA Boiling Point
The boiling point of a substance is the temperature at which it changes from liquid to gas. The boiling point of disodium edetate is not easy to measure because it decomposes before reaching its boiling point. However, some sources estimate that the boiling point of disodium edetate is around 614.2 °C at 760 mmHg pressure.
EDTA Melting Point
The melting point of a substance is the temperature at which it changes from solid to liquid. The melting point of disodium edetate depends on the degree of hydration and crystallization. The anhydrous form of disodium edetate has a melting point of about 240 °C, while the dihydrate form has a melting point of about 248 °C.
EDTA Density g/ml
The density of a substance is the mass per unit volume. The density of disodium edetate also varies with the degree of hydration and crystallization. The anhydrous form of disodium edetate has a density of about 0.86 g/ml, while the dihydrate form has a density of about 1.6 g/ml.
EDTA Molecular Weight
The molecular weight of a substance is another term for its molar mass, which is the mass of one mole of the substance. As mentioned above, the molar mass of disodium edetate is 292.24 g/mol, so its molecular weight is also 292.24 g/mol.
EDTA Structure
The structure of disodium edetate shows how its atoms are arranged and bonded in its molecule. disodium edetate has a central ethylenediamine group with four carboxylic acid groups attached to it. Each carboxylic acid group can lose a proton and form a negative charge, which can bind to a metal ion. The structure of disodium edetate can be represented by the following diagram:
EDTA Solubility
The solubility of a substance is the amount that can dissolve in a given solvent at a given temperature and pressure. The solubility of disodium edetate depends on the pH and the presence of metal ions in the solution. disodium edetate is more soluble in alkaline solutions than in acidic solutions because it forms more negative charges that can interact with water molecules. disodium edetate can also form complexes with metal ions, which can increase or decrease its solubility depending on the stability and charge of the complex. For example, at pH 7 and 25 °C, the solubility of disodium edetate in water is about 0.5 M (186 mg/ml), while the solubility of its calcium complex is about 0.02 M (7 mg/ml).
| Appearance | White crystalline solid |
| Specific gravity | Not available |
| Color | White |
| Odor | Odorless |
| Molar mass | 292.24 g/mol |
| Density | 1.6 g/ml (dihydrate), 0.86 g/ml (anhydrous) |
| Melting point | 248 °C (dihydrate), 240 °C (anhydrous) |
| Boiling point | 614.2 °C (decomposes) |
| Flash point | 325.2 °C |
| Water solubility | 0.5 M (186 mg/ml) at pH 7 and 25 °C |
| Solubility | Soluble in alkaline solutions, insoluble in organic solvents |
| Vapour pressure | 3.77 x 10^-12 mmHg at 25 °C |
| Vapour density | Not available |
| pKa | 2.0, 2.7, 6.2, 10.3 |
| pH | 4 to 6 (0.26 M solution) |
EDTA Safety Hazards
Disodium edetate is a synthetic organic compound that can chelate metal ions. It has various applications in medicine, industry, agriculture, and research. However, it also poses some risks to human health and the environment if not handled properly.
Disodium edetate can irritate the skin and eyes if it comes in contact with them. It can also cause nausea, vomiting, diarrhea, and abdominal pain if swallowed. It can harm the respiratory system if inhaled. It can affect the blood cells and the kidneys if absorbed into the body. It can be fatal in high doses.
Disodium edetate can also contaminate the soil and water if released into the environment. It can bind to essential metals and affect their availability for plants and animals. It can interfere with biological processes that depend on metal ions.
Use disodium edetate with caution and proper protective equipment. Store it in a cool, dry, and well-ventilated place. Dispose of it according to local regulations.
| Hazard symbols | |
| Safety description | S24/25: Avoid contact with skin and eyes |
| UN IDs | UN3077 (solid), UN3082 (liquid) |
| HS code | 29224985 |
| Hazard class | 9 (miscellaneous hazardous material) |
| Packing group | III (low danger) |
| Toxicity | LD50 oral rat: 2000 mg/kg |
EDTA Synthesis Methods
There are several methods to synthesize disodium edetate, but the most common one is the condensation of ethylenediamine with chloroacetic acid or its sodium salt.
The reaction involves two steps: first, the nucleophilic attack of ethylenediamine on chloroacetic acid or its sodium salt forms a monoamide intermediate. Second, the elimination of hydrochloric acid or sodium chloride forms a carboxylic acid group. To form disodium edetate, one can react with another equivalent of chloroacetic acid or its sodium salt.
Another method to synthesize disodium edetate is the oxidation of ethylenediamine with sodium hypochlorite in an alkaline solution. This method produces disodium edetate as a sodium salt and ammonia as a by-product.
Other methods to synthesize disodium edetate include the reaction of ethylenediamine with formaldehyde and sodium cyanide or the reaction of ethylenediamine with glyoxylic acid or its esters.
EDTA Uses
Disodium edetate is a synthetic organic compound that can chelate metal ions. It has various uses in different fields and industries. Some of the disodium edetate uses are:
- In medicine, disodium edetate can treat heavy metal poisoning by binding to the toxic metals and removing them from the body. It can also prevent blood clots and calcification in the arteries by chelating calcium ions.
- In food and beverage, disodium edetate can preserve the color, flavor, and texture of products by preventing oxidation and rancidity. It can also prevent discoloration and spoilage caused by metal ions.
- In cosmetics and personal care, disodium edetate can enhance the stability and efficacy of products by preventing microbial growth and metal-catalyzed reactions. It can also improve the appearance and feel of products by chelating minerals that cause hardness in water.
- In industry and research, disodium edetate can improve the performance and quality of products and processes by chelating metal ions that interfere with them. For example, it can prevent scale formation in boilers and pipes, improve the dyeing and printing of textiles, remove rust and stains from metals, and control pH and metal concentration in analytical methods.
Questions:
Q: What is EDTA?
A: disodium edetate is a synthetic organic compound that can chelate metal ions. It stands for ethylenediaminetetraacetic acid.
Q: How to prepare an EDTA solution?
A: To prepare a disodium edetate solution, weigh out the desired amount of disodium edetate and dissolve it in distilled water. Adjust the pH to 8.0 with sodium hydroxide.
Q: How to dissolve EDTA in water?
A: disodium edetate is soluble in water, but it dissolves slowly. To dissolve disodium edetate in water, heat the water to about 80 °C and stir the mixture until the disodium edetate dissolves completely.
Q: How to prepare 0.5 M EDTA?
A: To prepare 0.5 M disodium edetate, weigh out 73.06 g of disodium edetate and dissolve it in 800 mL of distilled water. Adjust the pH to 8.0 with sodium hydroxide and dilute the solution to 1 L with distilled water.
Q: What does EDTA do?
A: disodium edetate binds to metal ions and forms stable complexes with them. This prevents the metal ions from reacting with other substances or interfering with analytical methods.
Q: What does EDTA stand for?
A: disodium edetate stands for ethylenediaminetetraacetic acid, which is the name of the compound that has the formula [CH2N(CH2CO2H)2]2.
Q: How to calculate the hardness of water by EDTA titration?
A: To calculate the hardness of water by disodium edetate titration, titrate a known volume of water sample with a standard disodium edetate solution using a suitable indicator. Record the volume of disodium edetate used and use the following formula: Hardness (mg/L as CaCO3) = (Volume of EDTA x Molarity of EDTA x 1000) / Volume of water sample