Determination of quaternary ammonium salts in lead nitrate-copper(II) nitrate solution

Abstract

A method is described for determining the quaternary ammonium surfactants cetyltrimethylammonium bromide, tetradecyltrimethylammonium bromide and octadecyltrimethylammonium bromide by titration with sodium tetraphenylboron solution at pH 3, with methyl yellow as indicator. The error is within ±1 per cent. for the determination of the above quaternary ammonium surfactants either alone or in the presence of lead nitrate or copper(II) nitrate, or both.