METHOD FOR CONCENTRATION OF NAPHTHOLMONOSULFONIC ACIDS FROM AQUEOUS SOLUTIONS Russian patent published in 2006 - IPC C07C309/35 B01D11/04 G01N31/00 

FIELD: analytical chemistry, in particular organic material analysis.

SUBSTANCE: claimed method includes extraction with trioctylamine oxide (TOAO) in presence of ammonium sulfate, wherein mixture of trioctylamine oxide and melted cetyl alcohol in mass ratio of 15-20:85-80, respectively, is preliminary prepared, followed by dipping of sealed glass or polyethylene capsule having inner steel rod into obtained hot mixture. Further capsule with formed film containing trioctylamine oxide and cetyl alcohol is drawn out, cooled at room temperature and than placed in testing solution. Capsule is rotated at rate of 45-70 rpm for 20-25 min to concentrate naphtholmonosulfo acid and concentration coefficient K is determined by photometric method according to equation : K = m_film/m_sol, wherein m_film and m_sol are masses of mixed film of TOAO and cetyl alcohol and tested aqueous solution (g). Method of present invention is particularly useful in concentration of 1-naphthol-4-sulfonic acid, 1-naphthol-5-sulfonic acid, 2-naphthol-6-sulfonic acid in purified wastewater from azo dyes production. Said method makes it possible to increase of naphtholmonosulfonic acid concentration coefficient by 10 times and to decrease time of concentrate production by 3 times.

EFFECT: effective accelerated method for naphtholmonosulfonic acid concentration.

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