Determination of Surface-active Agent. III. Volumetric Determination of Anionic Surface-active Agent using Neutral Red as an Indicator.

Abstract

A new volumetric method of determination of anionic surface-active agent with cationic surface-active agent using Neutral red as an indicator at pH 8∼9 was studied. This method can be applied for the anionic surface-active agents or sulfate or sulfonate type, and not be applied for soaps. Addition of non-ionic surfactant and sodium sulfate scarcely influences the titration. The mechanism of this titration is also discussed.