Aluminon, the triammonium salt of aurintricarboxylic acid, is a dye often used to detect the presence of the aluminium ion in an aqueous solution.

Aluminon forms a red complex salt in combination with Al3+.

[1] In addition to its use in qualitative inorganic analysis, aluminon has applications in pigment production.

It forms brilliantly colored lake pigments with many metals.

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