Simplified spectrophotometric method using methylene blue for determining anionic surfactants: applications to the study of primary biodegradation in aerobic screening tests Jurado Alameda, Encarnación Fernández Serrano, Mercedes Núñez Olea, Josefa Luzón González, Germán Lechuga Villena, Manuela María In the present work, we propose a simplified spectrophotometric method for determining anionic surfactants, based on the formation of the ionic pair anionic surfactant-methylene blue (AS–MB). This method, in relation to the conventional analytic procedure, considerably reduces not only the quantity of chloroform used in extracting the ionic pair formed, but also the time and the quantity of sample necessary to perform the assay, eliminating the filtration stage. The method has been simplified by displacing the transfer equilibrium of the ionic pair AS–MB towards the organic phase, augmenting the volumetric relationship of chloroform/ sample. The method proposed has been applied in the study of primary biodegradation kinetics of linear alkylbenzenesulfonate (LAS). 2025-01-17T11:25:52Z 2025-01-17T11:25:52Z 2006-04-17 journal article E. Jurado , M. Fernandez-Serrano, J. Núnez-Olea, G. Luzón, M. Lechuga. Simplified spectrophotometric method using methylene blue for determining anionic surfactants: Applications to the study of primary biodegradation in aerobic screening tests. Chemosphere 65 (2006) 278–285 https://hdl.handle.net/10481/99516 https://doi.org/10.1016/j.chemosphere.2006.02.044 eng http://creativecommons.org/licenses/by-nc-nd/4.0/ embargoed access Attribution-NonCommercial-NoDerivatives 4.0 Internacional Elsevier