phthalein

[ thal-een, -ee-in, fthal- ]

noun

, Chemistry.

1. any of a group of compounds formed by treating phthalic anhydride with phenols, from which certain important dyes are derived.

phthalein

/ ˈθæl-; ˈfθæl-; -lɪɪn; ˈθeɪliːn /

noun

1. any of a class of organic compounds obtained by the reaction of phthalic anhydride with a phenol and used in dyes

phthalein

/ thăl′ēn′,thā′lēn′,fthăl′- /

1. Any of a group of chemical compounds formed by a reaction of phthalic anhydride with a phenol. They are used to derive certain synthetic dyes.

Word History and Origins

Origin of phthalein¹

First recorded in 1900–05; (na)phthale(ne) + -in ²

Word History and Origins

Origin of phthalein¹

C19: from phthal-, shortened form of naphthalene + -in

Example Sentences

When heated with caustic alkalis it yields dibromresorcin and dibrommonoresorcin-phthalein.

From Project Gutenberg

The phthalein on the day following the second venesection was 45 per cent in two hours.

From Project Gutenberg

The phthalein excretion is quite normal and the excretions of salt and nitrogen are also normal.

From Project Gutenberg