Abstract

In order to control the pollution by anionic surfactants in water, and detect anionic surfactants on-line, a simple, accurate and sensitive flow injection spectrophotometric method for simultaneous determination of anionic surfactant in water is proposed in this paper. The method is based on the ion associate formed between sodium dodecylbenzenesulfonate and ethyl violet. The absorbance of the complex is measured using an optical detector at 587nm. Chemical factors and FIA variables affecting the system are also discussed. Under the optimal conditions, the linear range of this method was 10.00-3000.00μg l-1; the detection limit was 0.25μg l-1; the relative standard deviation was 0.814%. This method is suitable for automatic and continuous analysis, and successfully applied to simultaneously determine the content of anionic surfactant in tannery effluent.