Surface active agents — Technical alkane sulfonates — Determination of alkane monosulfonates content by direct two-phase titration

The determination is carried out in a consisting of an aqueous phase and a chloroform phase, in the presence of sodium sulfate, by titration against a standard volumetric cationic-active solution (benzethonium chloride), in the presence of an indicator consisting of a mixture of a cationic dye (dimidium bromide) and an anionic dye (acid blue 1).