Two-Phase Titration Method for Cationic Surface Active Agents Determination with Use of 5-(3-Bromo-4-hydroxy-5-methoxyphenyl)-7,7-dimethyl-7H-indolo[1,2-a]quinolinium Perchlorate Dye

Abstract

Abstract The direct two-phase titration method with use of solvatochromic dye, i. e. 5-(3-bromo-4-hydroxy-5-methoxyphenyl)-7,7-dimethyl-7H-indolo[1,2-a]quinolinium perchlorate (1) for cationic surfactants determination is presented which is the modification of an earlier described procedure for anionic surface active substances detection. The method was tested on standard solution of benzethonium chloride (cationic detergent) which enables to estimate its accuracy as well as on few commercially available products to verify its utility. The influence of pH value of the probe on the titration endpoint determination was discussed and a simple solution of this problem has been proposed.