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| {{redirect|EDTA}}
| | Whenever inside search of the proper hemorrhoid treatment you will want to consider a few significant factors such as, which you you think you want, if there is a amazing amount of healing needed, and how extended it takes to get results. In this article you'll learn the answers to all of these concerns, giving you the answer you should find the right hemorrhoid treatment.<br><br>The 2nd [http://hemorrhoidtreatmentfix.com/external-hemorrhoids external hemorrhoids] is in the form of suppository. You have to insert the drug inside the rectum inside order to help healing the symptom. This system is considered to be superior since numerous sufferers have utilized it plus find it works well with them.<br><br>Start by taking certain procedures that may stop the hemorrhoids from worsening. This involves using soaps which are dye and perfume free. Rubbing the anal area can create things worse. Instead, employ moistened toilet paper plus blot the region after using the bathroom. After we shower, pat dry gently with a soft towel.<br><br>Having a superior bowel movement etiquette is without question 1 of the best techniques to avoid hemorrhoids. Everytime you feel the urge, do so without hindrance. Numerous delays of going to the rest room brings about constipation which causes you to strain difficult inside order to eliminate a bowels. As fast because you're completed, instantly receive up. Staying too long on the toilet seat will amplify stress on a veins. After your bowel movement, we could equally try sitting inside a tub with lukewarm water for 10 to 15 minutes to relax a rectum.<br><br>Right now, there are a lot of hemorrhoid treatments. And yes, there are the painless hemorrhoid treatments also accessible. Examples of that include utilize of petroleum jelly, the use of ointment phenylephrine or Preparation H, and even the easy utilize of soft cotton underwear. They are painless for with them we don't should go under the knife.<br><br>Or, try to apply phenylephrine or Preparation H to the region where you have hemorrhoid. According to certain experts, use of the ointment may be furthermore really effective. It can actually constrict the blood vessels plus lessen the redness and all.<br><br>Undergoing with these choices usually definitely expense we expensive. And for certain not all folks may afford to pay such operation. Then there are additionally hemorrhoids treatment which is found at house. With these hemorrhoid treatments we can be sure which you'll not invest too much. In most situations, people like to have all-natural treatment whilst the hemorrhoid continues to be on its mild stage. These natural treatments commonly help you in reducing the pain plus swelling. You do not have to be concerned because we apply or use them because they are easy and affordable. |
| {{chembox
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| | Watchedfields = changed
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| | verifiedrevid = 408562373
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| | ImageFile = EDTA.svg
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| | ImageFile_Ref = {{chemboximage|correct|??}}
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| | ImageName = Skeletal formula of ethylenediaminetetraacetic acid
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| | ImageFile1 = Sample of Ethylenediaminetetraacetic acid disodium salt.jpg
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| | ImageSize1 = 200
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| | ImageName1 = EDTA di-sodium salt
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| | ImageCaption1 = Disodium EDTA
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| | PIN =
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| | SystematicName = 2-({2-[Bis(carboxymethyl)amino]ethyl}(carboxymethyl)amino)acetic acid
| |
| | OtherNames = {{unbulleted list|Diaminoethane-tetraacetic acid|Edetic acid|Ethylenedinitrilo-tetraacetic acid|Versene}}
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| | Section1 = {{chembox Identifiers
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| | Abbreviations = EDTA, H<sub>4</sub>EDTA
| |
| | CASNo = 60-00-4
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| | CASNo_Ref = {{cascite|correct|CAS}}
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| | PubChem = 6049
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| | PubChem_Ref = {{pubchemcite|correct|pubchem}}
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| | ChemSpiderID = 5826
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| | ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
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| | UNII = 9G34HU7RV0
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| | UNII_Ref = {{fdacite|correct|FDA}}
| |
| | EINECS = 200-449-4
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| | UNNumber = 3077
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| | DrugBank = DB00974
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| | DrugBank_Ref = {{drugbankcite|correct|drugbank}}
| |
| | KEGG = D00052
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| | KEGG_Ref = {{keggcite|correct|kegg}}
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| | MeSHName = Edetic+Acid
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| | ChEBI = 42191
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| | ChEBI_Ref = {{ebicite|correct|EBI}}
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| | ChEMBL = 858
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| | ChEMBL_Ref = {{ebicite|correct|EBI}}
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| | RTECS = AH4025000
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| | ATCCode_prefix = S01
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| | ATCCode_suffix = XA05
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| | ATC_Supplemental = {{ATC|V03|AB03}} (salts)
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| | Beilstein = 1716295
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| | Gmelin = 144943
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| | SMILES = [o]:c(:[oH])CN(CCN(Cc(:[o]):[oH])Cc(:[o]):[oH])Cc(:[o]):[oH]
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| | SMILES1 = OC(=O)CN(CCN(CC(O)=O)CC(O)=O)CC(O)=O
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| | StdInChI = 1S/C10H16N2O8/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)
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| | StdInChI_Ref = {{stdinchicite|correct|chemspider}}
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| | StdInChIKey = KCXVZYZYPLLWCC-UHFFFAOYSA-N
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| | StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
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| }}
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| | Section2 = {{chembox Properties
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| | C = 10
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| | H = 16
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| | N = 2
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| | O = 8
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| | Appearance = Colourless crystals
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| | Density = 860 mg mL<sup>−1</sup> (at 20 °C)
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| | LogP = −0.836
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| | pKa = 1.782
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| | pKb = 12.215
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| }}
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| | Section3 = {{chembox Thermochemistry
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| | DeltaHf = −1.7654–−1.7580 MJ mol<small>−1</small>
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| | DeltaHc = −4.4617–−4.4545 MJ mol<small>−1</small>
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| }}
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| | Section4 = {{chembox Pharmacology
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| | AdminRoutes = {{unbulleted list|Intramuscular|Intravenous}}
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| }}
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| | Section5 = {{chembox Hazards
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| | GHSPictograms = {{gHS exclamation mark}}
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| | GHSSignalWord = '''WARNING'''
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| | HPhrases = {{h-phrases|319}}
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| | PPhrases = {{p-phrases|305+351+338}}
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| | EUIndex = 607-429-00-8
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| | EUClass = {{hazchem Xi}}
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| | RPhrases = {{r36}}
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| | SPhrases = {{s2}}, {{s26}}
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| | NFPA-H = 1
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| | NFPA-F = 0
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| | NFPA-R = 0
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| | LD50 = 2.580 g kg<sup>−1</sup> <small>(oral, rat)</small>
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| }}
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| | Section6 = {{chembox Related
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| | Function = alkanoic acids
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| | OtherFunctn = {{unbulleted list|[[Daminozide]]|[[Octopine]]}}
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| | OtherCpds = {{unbulleted list|[[Triethylenetetramine]]|[[Tetraacetylethylenediamine]]|[[PMDTA]]|[[Bis-tris propane]]}}
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| }}
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| }}
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| | |
| '''Ethylenediaminetetraacetic acid''', widely abbreviated as '''EDTA''' (for other names, see Table), is an [[aminopolycarboxylic acid]] and a colourless, water-soluble solid. Its [[conjugate base]] is named '''ethylenediaminetetraacetate'''. It is widely used to dissolve [[limescale]]. Its usefulness arises because of its role as a hexadentate ("six-toothed") [[ligand]] and [[chelating agent]], i.e. its ability to "sequester" [[metal]] [[ion]]s such as Ca<sup>2+</sup> and Fe<sup>3+</sup>. After being bound by EDTA, metal ions remain in solution but exhibit diminished reactivity. EDTA is produced as several salts, notably disodium EDTA and calcium disodium EDTA.
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| ==Synthesis==
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| The compound was first described in 1935 by Ferdinand Munz, who prepared the compound from [[ethylenediamine]] and [[chloroacetic acid]].<ref>F. Münz "Polyamino carboxylic acids to [[IG Farben|I. G. Farbenindustrie]], DE 718 981, 1935; US 2 130 505, 1938.</ref> Today, EDTA is mainly synthesised from [[ethylenediamine]] (1,2-diaminoethane), [[formaldehyde]], and [[sodium cyanide]].<ref>[http://www.chm.bris.ac.uk/motm/edta/synthesis_of_edta.htm Synthesis of EDTA]</ref> This route yields the sodium salt, which can be converted in a subsequent step into the acid forms:
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| :H<sub>2</sub>NCH<sub>2</sub>CH<sub>2</sub>NH<sub>2</sub> + 4 CH<sub>2</sub>O + 4 NaCN + 4 H<sub>2</sub>O → (NaO<sub>2</sub>CCH<sub>2</sub>)<sub>2</sub>NCH<sub>2</sub>CH<sub>2</sub>N(CH<sub>2</sub>CO<sub>2</sub>Na)<sub>2</sub> + 4 NH<sub>3</sub>
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| :(NaO<sub>2</sub>CCH<sub>2</sub>)<sub>2</sub>NCH<sub>2</sub>CH<sub>2</sub>N(CH<sub>2</sub>CO<sub>2</sub>Na)<sub>2</sub> + 4 HCl → (HO<sub>2</sub>CCH<sub>2</sub>)<sub>2</sub>NCH<sub>2</sub>CH<sub>2</sub>N(CH<sub>2</sub>CO<sub>2</sub>H)<sub>2</sub> + 4 NaCl
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| In this way, about 80M kilograms are produced each year. Impurities cogenerated by this route include [[glycine]] and [[nitrilotriacetic acid]]; they arise from reactions of the ammonia coproduct.<ref name="Ullmann">J. Roger Hart "Ethylenediaminetetraacetic Acid and Related Chelating Agents" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2005.{{DOI|10.1002/14356007.a10_095}}</ref>
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| ==Nomenclature==
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| To describe EDTA and its various [[Protonation|protonated forms]], chemists distinguish between EDTA<sup>4−</sup>, the [[conjugate base]] that is the [[ligand]], and H<sub>4</sub>EDTA, the [[precursor (chemistry)|precursor]] to that ligand. At very low pH (very acidic conditions) the fully protonated H<sub>6</sub>EDTA<sup>2+</sup> form predominates, whereas at very high pH or very basic condition, the fully deprotonated EDTA<sup>4−</sup> form is prevalent. In this article, the term EDTA is used to mean H<sub>4-x</sub>EDTA<sup>x-</sup>, whereas in its complexes EDTA<sup>4−</sup> stands for the tetra-deprotonated ligand.
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| ==Coordination chemistry principles==
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| [[Image:Metal-EDTA.svg|thumb|left|150px|Metal-EDTA [[chelate]]]]
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| In [[coordination chemistry]], EDTA<sup>4−</sup> is a member of the [[aminopolycarboxylic acid]] family of ligands. EDTA<sup>4−</sup> usually binds to a metal cation through its two amines and four carboxylates. Many of the resulting [[complex (chemistry)|coordination compound]]s adopt [[octahedral geometry]]. Although of little consequence for its applications, these octahedral complexes are [[Chirality (chemistry)|chiral]]. The anion [Co(EDTA)]<sup>−</sup> has been resolved into [[enantiomer]]s.<ref>Kirchner, S. Barium (Ethylenediaminetetracetato) Cobalt(III) 4-Hydrate" Inorganic Syntheses, 1957, Volume 5, pages 186-188. {{DOI|10.1002/9780470132364.ch52}}</ref> Many complexes of EDTA<sup>4−</sup> adopt more complex structures due to (i) the formation of an additional bond to water, i.e. seven-coordinate complexes, or (ii) the displacement of one carboxylate arm by water. Ferric complex of EDTA is seven-coordinate.<ref>J. M. López-Alcalá, M. C. Puerta-Vizcaíno, F. González-Vílchez, E. N. Duesler and R. E. Tapscott "A redetermination of sodium aqua[ethylenediaminetetraacetato(4-)]ferrate(III) dihydrate, Na[Fe(C<sub>10</sub>H<sub>12</sub>N<sup>2</sup>O<sup>8</sup>)(H<sup>2</sup>O)].2H<sub>2</sub>O" Acta Cryst. (1984). C40, 939-941. {{DOI|10.1107/S0108270184006338}}</ref> Early work on the development of EDTA was undertaken by [[Gerold Schwarzenbach]] in the 1940s.<ref>[http://www.chm.bris.ac.uk/motm/edta/edtah.htm Edta - Motm]</ref> EDTA forms especially strong complexes with Mn(II), Cu(II), Fe(III), Pb (II) and Co(III).<ref>{{cite book | last = Holleman | first = A. F. | coauthors = Wiberg, E. | title = Inorganic Chemistry | publisher = Academic Press | location = San Diego | year = 2001 | doi = | isbn = 0-12-352651-5}}</ref>
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| Several features of EDTA's complexes are relevant to its applications. First, because of its high [[denticity]], this ligand has a high affinity for metal cations:
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| :[Fe(H<sub>2</sub>O)<sub>6</sub>]<sup>3+</sup> + H<sub>4</sub>EDTA <math>\overrightarrow{\leftarrow}</math> [Fe(EDTA)]<sup>−</sup> + 6 H<sub>2</sub>O + 4 H<sup>+</sup> ([[Equilibrium constant|''K''<sub>eq</sub>]] = 10<sup>25.1</sup>)
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| Written in this way, the [[Stability constants of complexes|equilibrium quotient]] shows that metal ions compete with protons for binding to EDTA. Because metal ions are extensively enveloped by EDTA, their [[catalysis|catalytic properties]] are often suppressed. Finally, since complexes of EDTA<sup>4−</sup> are [[anion]]ic, they tend to be highly soluble in water. For this reason, EDTA is able to dissolve deposits of metal oxides and carbonates.
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| ==Uses==
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| ===Industry===
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| In industry, EDTA is mainly used to sequester metal ions in aqueous solution. In the [[Textile|textile industry]], it prevents metal ion impurities from modifying colours of dyed products. In the [[pulp and paper industry]], EDTA inhibits the ability of metal ions, especially Mn<sup>2+</sup>, from catalyzing the [[disproportionation]] of [[hydrogen peroxide]], which is used in "[[totally chlorine free|chlorine-free bleaching]]." In a similar manner, EDTA is added to some food as a [[preservative]] or stabilizer to prevent catalytic oxidative decoloration, which is catalyzed by metal ions.<ref name="furia1964">{{cite journal | author=Furia T | title=EDTA in Foods – A technical review | journal=Food Technology | volume=18 | issue=12 | pages=1874–1882 | year=1964}}</ref> In [[soft drink]]s containing [[ascorbic acid]] and [[sodium benzoate]], EDTA mitigates formation of [[benzene]] (a [[carcinogen]]).<ref>US Food and Drug Administration: Center for Food Safety and Applied Nutrition [http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/2006/ucm108636.htm Questions and Answers on the Occurrence of Benzene in Soft Drinks and Other Beverages]</ref>
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| The reduction of water hardness in laundry applications and the dissolution of scale in boilers both rely on EDTA and related [[complex (chemistry)|complexants]] to bind Ca<sup>2+</sup>, Mg<sup>2+</sup>, as well as other metal ions. Once bound to EDTA, these metal centers tend not to form precipitates or to interfere with the action of the [[soap]]s and [[detergent]]s. For similar reasons, cleaning solutions often contain EDTA.
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| The solubilization of ferric ions, at or below near neutral pH can be accomplished using EDTA. This property is useful in [[agriculture]] including hydroponics. However, given the pH dependence of ligand formation, EDTA is not helpful for improving Fe solubility in above neutral soils.<ref>Norvell and Lindsay, "Reactions of EDTA Complexes of Fe, Zn, Mn, and Cu with Soils1."</ref> Otherwise, at near-neutral pH and above, iron(III) forms insoluble salts, which are less bioavailable to susceptible plant species. Aqueous [Fe(edta)]<sup>−</sup> is used for removing ("scrubbing") [[hydrogen sulfide]] from gas streams. This conversion is achieved by oxidizing the hydrogen sulfur to elemental sulfur, which is non-volatile:
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| :2 [Fe(edta)]<sup>−</sup> + H<sub>2</sub>S → 2 [Fe(edta)]<sup>2−</sup> + [[sulfur|S]] + 2 H<sup>+</sup>
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| In this application, the ferric center is reduced to its ferrous derivative, which can then be reoxidized by air. In similar manner, [[nitrogen oxide]]s are removed from gas streams using [Fe(edta)]<sup>2−</sup>. The oxidizing properties of [Fe(edta)]<sup>−</sup> are also exploited in photography, where it is used to solubilize silver particles.<ref name="Ullmann" />
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| EDTA was used in the separation of the [[lanthanide metal]]s by ion-exchange chromatography. Perfected by F.H. Spedding et al. in 1954, the method relies on the steady increase in stability constant of the lanthanide EDTA complexes with atomic number. Using sulfonated polystyrene beads and copper(II) as a retaining ion, EDTA causes the lanthanides to migrate down the column of resin while separating into bands of pure lanthanide. The lanthanides elute in order of decreasing atomic number. Due to the expense of this method, relative to counter-current solvent extraction, ion-exchange is now used only to obtain the highest purities of lanthanide (typically greater than 4N, 99.99%).{{Citation needed|date=June 2009}}
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| ===Medicine===
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| EDTA is used to bind metal ions in the practice of [[chelation therapy]], e.g., for treating [[mercury poisoning|mercury]] and [[lead poisoning]].<ref>{{cite web | author = Ruth DeBusk ''et al.'' | title = Ethylenediaminetetraacetic acid (EDTA) | year = 2002 | url=http://www.umm.edu/altmed/articles/ethylenediaminetetraacetic-acid-000302.htm | accessdate=2007-07-25}}</ref> It is used in a similar manner to remove excess iron from the body. This therapy is used to treat the complication of repeated blood transfusions, as would be applied to treat [[thalassaemia]]. The [[Food and Drug Administration|U.S. FDA]] approved the use of EDTA for lead poisoning<ref>{{cite web|url=http://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?id=26310#nlm34067-9 |title=Calcium Disodium Versenate (Edetate Calcium Disodium) Injection [Graceway Pharmaceuticals, Llc] |publisher=Dailymed.nlm.nih.gov |date= |accessdate=2013-01-01}}</ref> on July 16, 1953, under the brand name of Versenate,<ref>{{cite web|url=http://www.accessdata.fda.gov/scripts/cder/drugsatfda/index.cfm |title=Drugs@FDA: FDA Approved Drug Products |publisher=Accessdata.fda.gov |date= |accessdate=2013-01-01}}</ref> which was licensed to the pharmaceutical company Riker. Alternative medical practitioners believe EDTA acts as a powerful [[antioxidant]] to prevent free radicals from injuring blood vessel walls, therefore reducing [[atherosclerosis]].<ref>{{cite web|url=http://www.umm.edu/altmed/articles/ethylenediaminetetraacetic-acid-000302.htm|title=Home > Medical Reference > Complementary Medicine > EDTA overview|work=University of Maryland Medical Center|accessdate=16 December 2009}}</ref> The [[Food and Drug Administration|U.S. FDA]] has not approved it for the treatment of atherosclerosis.<ref>{{cite web|url=http://www.fda.gov/Drugs/DrugSafety/PostmarketDrugSafetyInformationforPatientsandProviders/ucm113738.htm|title=Postmarket Drug Safety Information for Patients and Providers > Questions and Answers on Edetate Disodium (marketed as Endrate and generic products)|accessdate=16 December 2010}}</ref>
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| [[Dentist]]s and [[endodontist]]s use EDTA solutions to remove inorganic debris (smear layer) and lubricate the canals in endodontics. This procedure helps prepare root canals for obturation. Furthermore, EDTA solutions with the addition of a surfactant loosen up calcifications inside a root canal and allow instrumentation (canals shaping) and facilitate apical advancement of a file in a tight/calcified root canal towards the apex. It serves as a preservative (usually to enhance the action of another preservative such as [[benzalkonium chloride]] or [[thiomersal]]) in ocular preparations and eyedrops.<ref>See "les conservateurs en opthalmologie" Doctors Patrice Vo Tan & Yves lachkar, Librarie Médicale Théa.</ref> In evaluating [[kidney function]], the complex [Cr(edta)]<sup>−</sup> is administered intravenously and its filtration into the urine is monitored. This method is useful for evaluating [[glomerular filtration rate]].<ref>{{cite journal | doi = 10.1042/CS20020055 | author = Shirley, D.G., Walter, S.J. and Noormohamed, F.H. | title = Natriuretic effect of caffeine: assessment of segmental sodium reabsorption in humans. | journal = Clinical Science | volume = 103 | year = 2002 | issue = 5 | accessdate = 2010-06-18 | pages = 461–466 | pmid = 12401118}}</ref>
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| EDTA is used extensively in the analysis of blood. It is an [[anticoagulant]] for blood samples for [[Complete blood count|CBC/FBE]]s.
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| Laboratory studies also suggest that EDTA chelation may prevent collection of platelets on the lining of the vessel [such as arteries] (which can otherwise lead to formation of blood clots, which itself is associated with atheromatous plaque formation or rupture, and thereby ultimately disrupts blood flow). These ideas have so far been proven ineffective;<ref>{{cite web|url=http://www.quackwatch.org/01QuackeryRelatedTopics/chelationimp.html|title=EDTA Chelation Therapy for Atherosclerosis And Degenerative Diseases: Implausibility and Paradoxical Oxidant Effects|last=Green|first=Saul|coauthors=Wallace Sampson|date= December 14, 2002|work=Quackwatch|accessdate=16 December 2009}}</ref> however, a major clinical study of the effects of EDTA on coronary arteries is currently (2008) proceeding.<ref name="clinical study">{{cite web|url=http://www.clinicaltrials.gov/ct/show/NCT00044213?order=2 |title=Trial to Assess Chelation Therapy (TACT) - Full Text View |publisher=ClinicalTrials.gov |date= |accessdate=2013-01-01}}</ref> EDTA played a role in the [[O.J. Simpson murder case|O.J. Simpson trial]] when the defense alleged that one of the blood samples collected from Simpson's estate was found to contain traces of the compound.<ref>{{cite news|url=http://query.nytimes.com/gst/fullpage.html?sec=health&res=990CE4DD1F3DF935A15754C0A963958260|title=F.B.I. Disputes Simpson Defense on Tainted Blood|last=Margolock|first=David|date=July 26, 1995|work=The New York Times|pages=A12|accessdate=16 December 2009}}</ref>
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| EDTA is a slime dispersant, and has been found to be highly effective in reducing bacterial growth during implantation of [[intraocular lenses]] (IOLs).<ref>{{cite web|url=http://jac.oxfordjournals.org/content/early/2009/01/14/jac.dkn533.full |title=Impact of slime dispersants and anti-adhesives on in vitro biofilm formation of Staphylococcus epidermidis on intraocular lenses and on antibiotic activities |publisher=Jac.oxfordjournals.org |date= |accessdate=2013-01-01}}</ref>
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| ===Cosmetics===
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| In shampoos, cleaners and other personal care products EDTA salts are used as a sequestering agent to improve their stability in air.<ref name="lanigan2002" />
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| ===Laboratory applications===
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| In the laboratory, EDTA is widely used for scavenging metal ions: In [[biochemistry]] and [[molecular biology]], ion depletion is commonly used to deactivate [[metalloenzyme|metal-dependent enzyme]]s, either as an assay for their reactivity or to suppress damage to DNA or proteins.<ref>{{cite journal |title=A novel nuclease activity that is activated by Ca(2+) chelated to EGTA |last1=Dominguez |first1=K |last2=Ward |first2=WS |journal=[[Systems Biology in Reproductive Medicine]] |date=December 2009 |volume=55 |issue=5-6|doi=10.3109/19396360903234052 |pages=193–99}}</ref> In analytical chemistry, EDTA is used in [[complexometric titration]]s and analysis of [[water hardness]] or as a [[masking agent]] to sequester metal ions that would interfere with the analyses.
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| EDTA finds many specialized uses in the biomedical laboratories, such as in [[veterinary]] [[ophthalmology]] as an [[collagenase|anticollagenase]] to prevent the worsening of [[corneal ulcers in animals]]. In [[tissue culture]] EDTA is used as a chelating agent that binds to calcium and prevents joining of [[cadherins]] between cells, preventing clumping of cells grown in liquid suspension, or detaching adherent cells for [[passaging]]. In histopathology, EDTA can be used as a decalcifying agent making it possible to cut sections using a microtome once the tissue sample is demineralised.
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| EDTA is also known to inhibit a range of [[Metalloproteinase|metallopeptidases]], the method of inhibition occurs via the [[chelation]] of the metal ion required for catalytic activity.<ref>Auld D.S "Removal and replacement of metal ions in metallopeptidases " Methods Enzymol (1995) 248, 228-242.</ref> EDTA can also be used to test for bioavailability of heavy metals in sediments.
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| ===Toxicity===
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| EDTA exhibits low acute toxicity with {{LD50}} (rat) of 2.0 – 2.2 g/kg.<ref name="Ullmann"/> It has been found to be both [[Cytotoxicity|cytotoxic]] and weakly [[Genotoxicity|genotoxic]] in laboratory animals. Oral exposures have been noted to cause reproductive and developmental effects.<ref name="lanigan2002">{{cite journal|author=Lanigan RS and Yamarik TA | title=Final report on the safety assessment of EDTA, calcium disodium EDTA, diammonium EDTA, dipotassium EDTA, disodium EDTA, TEA-EDTA, tetrasodium EDTA, tripotassium EDTA, trisodium EDTA, HEDTA, and trisodium HEDTA | journal=Int J Toxicol. |volume=21 Suppl 2 |pages=95–142 |year=2002 | accessdate=2008-01-28|pmid=12396676|doi=10.1080/10915810290096522}}</ref> The same study by Lanigan<ref name="lanigan2002" /> also found that both dermal exposure to EDTA in most cosmetic formulations and inhalation exposure to EDTA in aerosolized cosmetic formulations would produce exposure levels below those seen to be toxic in oral dosing studies.
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| ==Environmental fate==
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| ===Abiotic degradation===
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| EDTA is in such widespread use that questions have been raised whether it is a [[persistent organic pollutant]]. While EDTA serves many positive functions in different industrial, pharmaceutical and other avenues, the longevity of EDTA can pose serious issues in the environment. The degradation of EDTA is slow. It mainly occurs [[abiotically]] in the presence of sunlight.<ref>{{citation|author=Bucheli-Witschel, M.; Egli, T.
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| |journal= FEMS Microbiology Reviews
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| |title=DAB: Environmental Fate and Microbial Degradation of Aminopolycarboxylic Acids
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| |volume=25
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| |pages=69–106
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| |year=2001
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| }}</ref>
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| The most important process for the elimination of EDTA from surface waters is direct [[photolysis]] at wavelengths below 400 nm.<ref>{{Cite thesis |last= Kari |first= F.G|title= Umweltverhalten von Ethylenediamintetraacetat (EDTA) under spezieller Berucksuchtigung des photochemischen Ab-baus.|type=Ph.D | |year= 1994 |publisher= Swiss Federal Institiute of Technology}}</ref> Depending on the light conditions, the photolysis [[half-life|half-lives]] of Fe(III)EDTA in surface waters can range as low as 11.3 minutes up to more than 100 hours.<ref>{{cite journal |last= Frank|first= R|last2= Rau|first2=H |year=1989 |title= Photochemical transformation in aqueous solution and possible environmental fate of ethylenediaminetetraacetatic acid (EDTA)|url= |journal= Ecotoxicology and Environmental Safety |volume= 19 |pages=55–63}}</ref> Degradation of FeEDTA, but not EDTA itself, produces Fe complexes of ED3A, EDDA, and EDMA- 92% of EDDA and EDMA biodegrades in 20 hours while ED3A displays significantly higher resistance. Many environmentally-abundant EDTA species (e.g., Mg<sup>2+</sup>, Ca<sup>2+</sup>) are more persistent.
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| ===Biodegradation===
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| In many industrial wastewater treatment plants, EDTA elimination can be achieved at about 80% using [[microorganisms]].<ref>{{cite journal |last= Kaluza|first= U|last2= Klingelhofer|first2=P |first3 = Taeger |last3=K |year=1998 |title= Microbial degradation of EDTA in an industrial wastewater treatment plant |url = http://www.sciencedirect.com/science/article/pii/S0043135498000487# |journal= Water Research |volume= 32 |pages=2843–2845 |doi=10.1016/S0043-1354(98)00048-7}}</ref> Resulting byproducts are ED3A and IDA – suggesting that both the backbone and acetyl groups were attacked. Some microorganisms have even been discovered to form nitrates out of EDTA but degrade optimally at moderately alkaline conditions of pH 9.0-9.5.<ref>{{cite journal |last= VanGinkel|first= C.G |last2= Vandenbroucke|first2=K.L |first3 = Troo |last3=C.A |year=1997 |title= Biological removal of EDTA in conventional activated-sludge plants operated under alkaline conditions |url = http://www.sciencedirect.com/science/article/pii/S0960852496001587 |journal= Bioresources Technology |volume= 32 |pages=2843–2845 |doi=10.1016/S0960-8524(96)00158-7}}</ref>
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| Several bacterial strains isolated from sewage treatment plants efficiently degrade EDTA. Specific strains include [[Agrobacterium]] radiobacter ATCC 55002<ref>{{cite journal |last= Lauff|first= J.J. |last2= Steele|first2=D.B |first3 = Coogan |last3=L.A |first4 = Breitfeller |last3=J.M|year=1990 |title= Degradation of the ferric chelate of EDTA by a pure culture of an Agrobacterium sp.. |url = http://aem.asm.org/content/56/11/3346.full.pdf |journal= Applied Environmental Microbiology |volume= 56 |pages=3346–3353 |issue=11}}</ref> and the sub-branches of [[Proteobacteria]] like BNC1, BNC2 <ref name="Nortemannl 1992 671–676">{{cite journal |last= Nortemannl|first= B |year=1992 |title= Total degradation of EDTA by mixed culturesand a bacterial isolate |url = http://aem.asm.org/content/58/2/671.full.pdf |journal= Applied Environmental Microbiology |volume= 58 |pages=671–676 |issue=2}}</ref> and strain DSM 9103.<ref>{{cite speech |title=Degradation of EDTA by a bacterial isolate. Poster presented at the 45th Annual Meeting of the Swiss Society for Microbiology |author=Witschel, M., Weilemann, H.-U and Egli, T. |date=1995 |location= Lugano, Switzerland}}</ref> The three strains share similar properties of [[aerobic respiration]] and are classified as [[gram-negative bacteria]]. Unlike photolysis, the chelated species is not exclusive to Fe(III) in order to be degraded. Rather, each strain uniquely consumes varying metal-EDTA complexes through several enzymatic pathways. Agrobacterium radiobacter only degrades Fe(III) EDTA <ref name="Nortemannl 1992 671–676"/> while BNC1 and DSM 9103 are not capable of degrading Fe(III) EDTA and are more suited for CaEDTA, BaEDTA,MgEDTA, and MnEDTA.<ref>{{cite journal |last= Hennekenl|first= L |last2=Nortemann |first2=B |last3 = Hempel |first3=D.C |year=1995 |title= Influence of physiological conditions on EDTA degradation |url = http://download.springer.com/static/pdf/471/art%253A10.1007%252FBF00164501.pdf?auth66=1387152164_22c4ed152ad7db94d1191be672b2584c&ext=.pdf |journal= Applied Environmental Microbiology |volume= 44 |pages=190*197}}</ref> Free EDTA, as well as complexes with Zn2+, Cu2+, Ni2+, Co2+, and Fe3+, follow a separate degradation pathway and require the dissociation of the complex before degradation – measurable by the [[dissociation constant|dissociation rate constant]].
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| ==Alternatives to EDTA==
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| Interest in environmental safety has brought up concerns about biodegradability in [[aminopolycarboxylates]] such as EDTA. For example, under the [[International Organization for Standardization]] 28-day 7827 test Austrian paper and pulp industries must use chelating agents that have a biodegradation levels over 70-80%.<ref name=intech>{{cite web
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| | accessdate=2013-12-12
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| | url=http://www.intechopen.com/download/get/type/pdfs/id/20357
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| | format=PDF
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| | title=Chelating Agents of a New Generation as an Alternative to Conventional Chelators for Heavy Metal Ions Removal from Different Waste Waters
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| | publisher=InTech
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| }}</ref> An increased interest in safety has led to the development and research of new alternative chelating ligands which can still bind strongly to metal ions but also have a higher biodegradability and a lower content of nitrogen.<ref name="intech"/>
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| ===Iminodisuccinic acid (IDS)===
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| Commercially used since 1998, iminodisuccinic (IDS) acid biodegrades about 80% after only 7 days. IDS binds to calcium exceptionally well and forms stable compounds with other heavy metal ions. In addition to having a lower toxicity after chelation, the production of IDS is environment-friendly.<ref name="intech"/> Specifically, IDS is degraded through the use of IDS-epimerase and C-N [[lyase]] found in [[Agrobacterium tumefaciens]] (BY6) which can be harvested on a large scale. Additionally, the reactions catalyzed by both enzymes does not require any [[cofactors]] and can thus be applied directly.<ref>{{citation|author=Cokesa, Z.; Knackmuss, H.; Rieger P.
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| |journal= Appl. Environ Microbiol.
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| |title=Biodegradation of All Stereoisomers of the EDTA Substitute Iminodisuccinate by Agrobacterium Tumefaciens BY6 Requires an Epimerase and a Stereoselective C-N Lyase
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| |volume=70
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| |pages=3941–3947
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| |year=2004
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| }}</ref>
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| ===Polyaspartic acid===
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| [[Polyaspartic acid]], marketed as Baypure DS 100, is also produced in an environmentally friendly manner. DS, like IDS binds to calcium and other heavy metal ions. DS has a higher value of 7.2 meq/g than does EDTA, which only has 6.0 meq/g.<ref name="intech"/> While DS has a higher theoretical capacity, in practical applications it exhibits low efficiency in lower ion concentration solutions. DS has many practical applications including corrosion inhibitors, waste water additives, and agricultural polymers. A Baypure based laundry detergent was the first laundry detergent in the world to achieve the EU flower ecolable.<ref name="intech"/>
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| ===Ethylenediamine-N,N’-disuccinic acid (EDDS)===
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| As a structural isomer of EDTA, [[EDDS|ethylenediamine-N,N’-disuccinic acid]] can exist three [[isomers]]: (S,S), (R,S)/(S,R) and (R,R), but only the S,S-isomer is readily biodegradable. EDDS exhibits a surprisingly high rate biodegradation at 83% in 20 days. Biodegradation rates also varies the different metal ions chelated. For example, the complexes of lead and zinc with EDDS have relatively the same stability but the lead complex is biodegrades more efficiently than the zinc complex.<ref name="intech"/> As of 2002, EDDS has been commercially prominent in Europe on a large scale with an estimated demand rate increase of about 15% each year.<ref name="intech"/>
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| ===Methylglycinediacetic acid (MGDA)===
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| Produced from BASF, methylglycinediacetic acid (MGDA) is produced from from [[glycine]].<ref name="intech"/> MGDA has a high rate of biodegradation >68%, but unlike many other chelating agents can degrade without the assistance of adapted bacteria. Additionally, unlike EDDS or IDS, MGDA can withstand higher temperatures while maintaining a high stability as well as the entire pH range. As a result, the chelating strength of MGDA is stronger than many commercial chelating agents.<ref name="intech"/>
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| ===L-glutamic acid N,N-diacetic acid, tetra sodium salt (GLDA)===
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| Aminopolycarboxylate-based chelates are used to control metal ions in water-based systems.
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| ==Methods of detection and analysis==
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| The most sensitive method of detecting and measuring EDTA in biological samples is selected-reaction-monitoring [[capillary electrophoresis|capillary-electrophoresis]] [[liquid chromatography-mass spectrometry|mass-spectrometry]] (abbreviation SRM-CE/MS), which has a [[detection limit]] of 7.3 ng/mL in human plasma and a [[Detection limit|quantitation limit]] of 15 ng/mL.<ref name="sheppard">{{cite journal | author = Robin L. Sheppard, and Jack Henion | title = Determining EDTA in Blood | journal = Analytical Chemistry | volume = 69 | pages = 477A–480A | year = 1997 | url=http://pubs.acs.org/hotartcl/ac/97/aug/det.html|accessdate=2007-07-25 |format= – <sup>[http://scholar.google.co.uk/scholar?hl=en&lr=&q=intitle%3ADetermining+EDTA+in+Blood&as_publication=Analytical+Chemistry&as_ylo=1997&as_yhi=1997&btnG=Search Scholar search]</sup>|work= | pmid = 9253241 | issue = 15 | doi=10.1021/ac971726p
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| }} {{Dead link|date=April 2009}} {{Dead link|date=September 2010|bot=H3llBot}}</ref> This method works with sample volumes as small as ~7-8 nL.<ref name="sheppard" />
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| EDTA has also been measured in non-alcoholic beverages using [[High-performance liquid chromatography|high performance liquid chromatography]] (HPLC) at a level of 2.0 μg/mL.<ref>{{cite journal | author = S. Loyaux-Lawniczak, J. Douch, and P. Behra | title = Optimisation of the analytical detection of EDTA by HPLC in natural waters | journal = Fresenius' J. Anal. Chem. | volume = 364 | issue = 8 | pages = 727–731 | year = 1999 | url=http://cat.inist.fr/?aModele=afficheN&cpsidt=1898737|accessdate=2007-07-25 |work=
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| | doi = 10.1007/s002160051422
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| }}</ref><ref>{{cite journal | author = Carolina E. Cagnasso, Laura B. López, Viviana G.
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| Rodríguez and Mirta E. Valencia | title = Development and validation of a method for the determination of EDTA in non-alcoholic drinks by HPLC | journal = Journal of Food Composition and Analysis | volume = 20 | issue = 3-4 |date=May 2006 | doi=10.1016/j.jfca.2006.05.008 | accessdate = 2007-07-25 | page = 248
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| }}</ref>
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| ==See also==
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| * [[BAPTA]]
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| * [[DTPA]]
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| * [[EGTA (chemical)|EGTA]]
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| *
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| ==References==
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| {{reflist|2}}
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| ==External links==
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| * The [[MEROPS]] online database for peptidases and their inhibitors: [http://merops.sanger.ac.uk/cgi-bin/smi_summary?mid=J00149 EDTA]
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| * {{cite journal |author=Lanigan RS, Yamarik TA |title=Final report on the safety assessment of EDTA, calcium disodium EDTA, diammonium EDTA, dipotassium EDTA, disodium EDTA, TEA-EDTA, tetrasodium EDTA, tripotassium EDTA, trisodium EDTA, HEDTA, and trisodium HEDTA |journal=Int. J. Toxicol. |volume=21 Suppl 2 |issue= |pages=95–142 |year=2002 |pmid=12396676 |doi=10.1080/10915810290096522}}
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| * [http://www.chm.bris.ac.uk/motm/edta/edtah.htm EDTA: Molecule of the Month]
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| * [http://www.chem.utk.edu/~chem319/Experiments/Exp6.pdf EDTA Determination of Total Water Hardness]
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| * [http://www.scielo.br/scielo.php?pid=S0100-40422003000600020&script=sci_arttext EDTA: the chelating agent under environmental scrutiny, Química Nova, Nov.-Dec., 2003 (text version)]
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| * [http://www.scielo.br/pdf/qn/v26n6/a20v26n6.pdf EDTA: the chelating agent under environmental scrutiny, Química Nova, Nov.-Dec., 2003 (PDF version)]
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| {{Antidotes}}
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| {{antithrombotics}}
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| {{Chelating agents}}
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| {{Endodontology}}
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| {{Consumer Food Safety}}
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| {{DEFAULTSORT:Ethylenediaminetetraacetic Acid}}
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| [[Category:Acetic acids]]
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| [[Category:Amines]]
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| [[Category:Antidotes]]
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| [[Category:Chelating agents]]
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| [[Category:Photographic chemicals]]
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| [[Category:Preservatives]]
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| [[Category:World Health Organization essential medicines]]
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