The Photometric Determination of Quaternary Ammonium Salts and of Certain Amines by Compound Formation with Indicators

Abstract

Summary Published methods for the determination of quaternary ammonium compounds by (a) titration with anionic surface-active agents, and (b) measuring the change in colour intensity produced in an indicator in aqueous solution, have been found inapplicable to compounds of molecular weight lower than that of cetrimide. The indicator extraction method has been studied in some detail and the results of variations of conditions and the effects produced by interfering substances described and discussed. A general indicator extraction method is proposed which is applicable to all quaternary compounds except those of very low molecular weight.