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==Applications==
==Applications==


When used as an indicator in an [[Ethylenediaminetetraacetic_acid|EDTA]] titration, the characteristic blue [[Endpoint (chemistry)|end-point]] is reached when sufficient EDTA is added and metal ions is [[chelated]] by EDTA, leaving the free indicator molecule.
When used as an indicator in an [[Ethylenediaminetetraacetic_acid|EDTA]] titration, the characteristic blue [[Endpoint (chemistry)|end-point]] is reached when sufficient EDTA is added and the metal ions are [[chelated]] by EDTA, leaving the free indicator molecule.


Eriochrome Black T has also been used to detect the presence of rare earth metals.<ref>{{cite journal | author = Dubenskaya, L. O. and Levitskaya, G. D.| title = Use of eriochrome black T for the polarographic determination of rare-earth metals | journal = Journal of Analytical Chemistry | issn = 1061-9348 | year = 1999 | volume = 54 | pages = 655&ndash;657 | issue = 7 | url = http://cat.inist.fr/?aModele=afficheN&cpsidt=1896853}}</ref>
Eriochrome Black T has also been used to detect the presence of rare earth metals.<ref>{{cite journal | author = Dubenskaya, L. O. and Levitskaya, G. D.| title = Use of eriochrome black T for the polarographic determination of rare-earth metals | journal = Journal of Analytical Chemistry | issn = 1061-9348 | year = 1999 | volume = 54 | pages = 655&ndash;657 | issue = 7 | url = http://cat.inist.fr/?aModele=afficheN&cpsidt=1896853}}</ref>

Revision as of 09:19, 10 October 2013

Eriochrome Black T
Wireframe model of an eriochrome black T minor tautomer
Sample of Eriochrome Black T
Names
Preferred IUPAC name
Sodium 4-[(1-hydroxynaphthalen-2-yl-

hydrazinylidene]-7-nitro-3-oxo-Y-naphthalene-

1-sulfonate
Systematic IUPAC name
Sodium 4-[2-(1-hydroxynaphthalen-2-yl)

hydrazin-1-ylidene]-7-nitro-3-oxo-3,4-

dihydronaphthalene-1-sulfonate
Other names
Sodium 4-[2-(1-hydroxynaphthalen-2-yl)

hydrazin-1-ylidene]-7-nitro-3-oxonaphthalene-
1-sulfonate
Solochrome Black T

ET-00
Identifiers
3D model (JSmol)
Abbreviations EBT
4121162
ChemSpider
ECHA InfoCard 100.015.683 Edit this at Wikidata
EC Number
  • 217-250-3
MeSH Eriochrome+black+T
RTECS number
  • QK2197000
UN number 2923
  • InChI=1S/C20H13N3O7S.Na/c24-17-10-18(31

    (28,29)30)15-9-12(23(26)27)6-7-14(15)19
    (17)22-21-16-8-5-11-3-1-2-4-13(11)20(16)

    25;/h1-10,21,25H,(H,28,29,30);/q;+1/p-1 ☒N
    Key: JHUJLRKQZAPSDP-UHFFFAOYS
    A-M ☒N
  • InChI=1/C20H13N3O7S.Na/c24-17-10-18(31(28,29)30)15-9-12(23(26)27)6-7-14(15)19(17)22-21-16-8-5-11-3-1-2-4-13(11)20(16)25;/h1-10,24-25H,(H,28,29,30);/q;+1/p-1/b22-21+;
    Key: AMMWFYKTZVIRFN-YJURRCIZBT
  • InChI=1S/C20H13N3O7S.Na/c24-17-10-18(31(28,29)30)15-9-12(23(26)27)6-7-14(15)19(17)22-21-16-8-5-11-3-1-2-4-13(11)20(16)25;/h1-10,24-25H,(H,28,29,30);/q;+1/p-1/b22-21+;
    Key: AMMWFYKTZVIRFN-QUABFQRHSA-M
  • [Na+].OC1=C(NN=C2C(=O)C=C(C3=C2C
    C2=C1C=CC=C2
  • [Na+].[O-]S(=O)(=O)c3cc(O)c(/N=N/c2ccc1ccccc1c2O)c4ccc(cc34)[N+]([O-])=O
Properties
C20H12N3O7SNa
Molar mass 461.381 g/mol
Appearance Dark red/brown powder
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
☒N verify (what is checkY☒N ?)

Eriochrome Black T is a complexometric indicator that is part of the complexometric titrations, e.g. in the water hardness determination process. It is an azo dye. Eriochrome is a trademark of Ciba-Geigy.[1]

In its protonated form, Eriochrome Black T is blue. It turns red when it forms a complex with calcium, magnesium, or other metal ions.

EBT is blue in a buffered solution at pH 10. It turns red when Ca2+ ions are added.

Applications

When used as an indicator in an EDTA titration, the characteristic blue end-point is reached when sufficient EDTA is added and the metal ions are chelated by EDTA, leaving the free indicator molecule.

Eriochrome Black T has also been used to detect the presence of rare earth metals.[2]

References

  1. ^ http://www.bphchem.com/products/eriochrome_black_t_indicator_powder.html
  2. ^ Dubenskaya, L. O. and Levitskaya, G. D. (1999). "Use of eriochrome black T for the polarographic determination of rare-earth metals". Journal of Analytical Chemistry. 54 (7): 655–657. ISSN 1061-9348.{{cite journal}}: CS1 maint: multiple names: authors list (link)
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