Photometric determination of sulphated and sulphonated anionic surfactants

Abstract

A number of classes of sulphated and sulphonated anionic surfactants have been determined by photometric titration with the cationic surfactant Hyamine 1622. The results obtained are within ±5% of the corresponding results obtained by the two-phase mixed indicator titration procedure that is the current ISO method (ISO 2271). A photometric approach offers considerable advantages over the two-phase titration. These include a single aqueous phase, a non-operator dependent mode of detection and a 50% or more reduction in sample analysis time. The repeatability of the photometric method is similar to that obtained by experienced operators using the two-phase titration.