Sequential determination of anionic-type detergents by complexation with methylene blue using dual high speed counter-current chromatography

► We made a sequential analysis system for trace detergent. ► We confirmed that the system has great advantages over conventional method. ► Most advantages are simple, safe and high-performance method for determination. ► The system is highly sensitive and it is possible to measure a lot of samples continuously. ► The system was successively applied for the determination of detergents in river water.