'Phthalein' definitions:
Definition of 'Phthalein'
From: GCIDE
- Phthalein \Phthal"e*in\, n. [See Phthalic.] (Chem.) One of a series of artificial organic dyes made as condensation products of the phenols with phthalic acid, and well represented by phenolphthalein. Their alkaline solutions are fluorescent. [1913 Webster]
- Phenol phthalein, a white or yellowish white crystalline substance made from phthalic acid and phenol. Same as phenolphthalein. [1913 Webster + PJC]