Title: Aluminon
CAS Registry Number: 569-58-4
CAS Name: 5-[(3-Carboxy-4-hydroxyphenyl)(3-carboxy-4-oxo-2,5-cylohexadien-1-ylidene)methyl]-2-hydroxybenzoic acid triammonium salt
Additional Names: 3-[bis(3-carboxy-4-hydroxyphenyl)methylene]-6-oxo-1,4-cyclohexadiene-1-carboxylic acid triammonium salt; ammonium salt of aurintricarboxylic acid
Trademarks: Lysofon (Lafon)
Molecular Formula: C22H23N3O9
Molecular Weight: 473.43
Percent Composition: C 55.81%, H 4.90%, N 8.88%, O 30.42%
Literature References: Prepd by reacting sodium nitrite with salicylic acid and adding formaldehyde, then treating with ammonia: G. B. Heisig, W. M. Lauer, Org. Synth. coll. vol. I, 54 (2nd ed., 1941).
Properties: Yellowish-brown, glassy powder. Freely sol in water.
Use: Forms brilliantly colored lakes with aluminum, chromium, iron, beryllium. Generally used for the detection and colorimetric estimation of aluminum in water, foods, tissues. Cf. Scherrer, Mogerman, J. Res. Natl. Bur. Stand. 21, 105 (1938).
Therap-Cat: Pharyngeal aerosol spray.
Aluminum Acetate Solution Aluminum Acetotartrate Aluminum Alkyls Aluminum Ammonium Sulfate Aluminum Antimonide

CAS number 569-58-4 YesY
PubChem 2734958
ChemSpider 2016698 YesY
Jmol-3D images Image 1
Molecular formula C22H23N3O9
Molar mass 473.43 g/mol
Appearance yellow-brown crystals, red in aqueous solution
Solubility in other solvents freely soluble in H2O
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Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Infobox references

Aluminon, the triammonium salt of aurintricarboxylic acid, is a dye commonly used to detect the presence of the aluminium ion in an aqueous solution. In addition to its use in qualitative inorganic analysis, aluminon has applications in pigment production. It forms brilliantly colored lake pigments with aluminum, chromium, iron, and beryllium.

Aluminon is prepared by reacting sodium nitrite with salicylic acid, adding formaldehyde, then treating with ammonia.[1]