Ilosvay reagent

I·los·vay re·a·gent

(i-los'vā),
sulfanilic acid 0.5, dissolved in dilute acetic acid 150, mixed with naphthylamine 1, and dissolved in boiling water 20; the blue sediment that forms is dissolved in dilute acetic acid 150; a few drops of this reagent added to water, saliva, or other fluid to be tested will produce a red color if nitrites are present.

Ilosvay,

Lajos de, Hungarian chemist, 1851–.
Ilosvay reagent - test for nitrites.