ABSTRACT
Surfactants are the active ingredients of laundry and cleaning detergents, hard surface cleaners, and shampoos. After use, consumer product ingredients are discharged directly into municipal sewers and thence to treatment plants, where most of the surfactants are removed by adsorption and biodegradation. Colorimetric methods are typically based on the formation of a chloroform-extractable ion-association complex between the anionic surfactant and a cationic dye, followed by spectrophotometric measurement of the intensity of the extracted colored complex. Methylene blue active substances is the most widely accepted sumparameter for measuring the concentration of anionic surfactants in environmental samples. Methylene blue is by far the most widely used cationic dye for determining the concentration of anionic surfactants in biodegradation liquors and environmental samples. Linear Alkylbenzene Sulfonate (LAS) is the major anionic surfactant used in domestic detergents. High-Performance Liquid Chromatography has been widely applied to measure the concentration of LAS in a broad range of environmental samples.
