title: Simplified spectrophotometric method using methylene blue for determining anionic surfactants: applications to the study of primary biodegradation in aerobic screening tests.
abstract: 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).
authors.affiliation: Department of Chemical Engineering, Faculty of Sciences, University of Granada, Campus Fuentenueva s/n, 18071 Granada, Spain. ejurado@ugr.es
authors.forename: E
authors.initials: E
authors.lastname: Jurado
authors.forename: M
authors.initials: M
authors.lastname: Fernández-Serrano
authors.forename: J
authors.initials: J
authors.lastname: Núñez-Olea
authors.forename: G
authors.initials: G
authors.lastname: Luzón
authors.forename: M
authors.initials: M
authors.lastname: Lechuga
mesh_terms: D017738:Alkanesulfonic Acids / Q000032:analysis* / Q000378:metabolism; D000838:Anions; D001673:Biodegradation, Environmental; D004784:Environmental Monitoring; D007700:Kinetics; D008751:Methylene Blue / Q000737:chemistry*; D013053:Spectrophotometry / Q000379:methods; D013501:Surface-Active Agents / Q000032:analysis* / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000378:metabolism
chemical_list: D017738:Alkanesulfonic Acids; D000838:Anions; D013501:Surface-Active Agents; D014874:Water Pollutants, Chemical; C030641:alkylbenzyl sulfonic acid; D008751:Methylene Blue