Separation of anionic surfactants using aqueous and nonaqueous capillary electrophoresis

Capillary electrophoresis is well suited for the analysis of anionic surfactants such as alkyl sulfates, ether sulfates, and sulfonates in commercial products. Because of the lack of absorbing constituents in the analytes, chromophores are necessary as a background for indirect photometric detection. The influence of various absorbing buffer components and their concentration and pH has been investigated. For improved separation efficiency, organic solvents in different contents, up to 100%, have been used. Applications to the analysis of household detergents and toiletries are described. Sodium dodecyl sulfate (SDS) could be determined with a detection limit of 4.7 x 10(-6) mol/L.