phthalein

American  

[thal-een, -ee-in, fthal-] / ˈθæl in, -i ɪn, ˈfθæl- /

noun

Chemistry.

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

---

phthalein British  

/ 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 Scientific  

/ 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.

---

Etymology

Origin of phthalein

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

Example Sentences

Phthalein, thal′e-in, n. one of a very important class of dye-yielding materials formed by the union of phenols with the anhydride of phthalic acid.—adj.

From Project Gutenberg

Phthal′in, a colourless crystalline compound obtained by reducing phthalein.

From Project Gutenberg

The phthalein output is below normal.

From Project Gutenberg

As the case advances the phthalein output becomes less and less, until a period is reached when there are only traces or complete suppression at the end of a two-hour period.

From Project Gutenberg

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

From Project Gutenberg