title: The aquatic toxicity of anionic surfactants to Daphnia magna--a comparative QSAR study of linear alkylbenzene sulphonates and ester sulphonates.
abstract: This paper develops quantitative structure activity relationships (QSARs) for the acute aquatic toxicity of the anionic surfactants linear alkylbenzene sulphonates (LAS) and ester sulphonates (ES) to Daphnia magna, the aim being to investigate the modes of action by comparing the QSARs for the two types of surfactant. The generated data for ES have been used to develop a QSAR correlating toxicity with calculated log P values: log(1/EC50)= 0.78 log P+1.37. This equation has an intercept 1.1 log units lower than a QSAR for linear alkylbenzene sulphonates (LAS). The findings suggest that either ES surfactants act by a different mode of action to LAS and other anionic surfactants or the log P calculation method introduces a systematic overestimate when applied to ES.
authors.affiliation: SEAC, Unilever Colworth, Sharnbrook, Bedfordshire, MK44 1LQ, United Kingdom. geoff.hodges@unilever.com
authors.forename: Geoff
authors.initials: G
authors.lastname: Hodges
authors.forename: David W
authors.initials: DW
authors.lastname: Roberts
authors.forename: Stuart J
authors.initials: SJ
authors.lastname: Marshall
authors.forename: John C
authors.initials: JC
authors.lastname: Dearden
mesh_terms: D017738:Alkanesulfonic Acids / Q000737:chemistry / Q000633:toxicity*; D000818:Animals; D000838:Anions; D003621:Daphnia / Q000187:drug effects*; D004952:Esters / Q000737:chemistry / Q000633:toxicity; D006868:Hydrolysis; D008823:Micelles; D021281:Quantitative Structure-Activity Relationship; D013501:Surface-Active Agents / Q000737:chemistry* / Q000633:toxicity*; D014874:Water Pollutants, Chemical / Q000633:toxicity
chemical_list: D017738:Alkanesulfonic Acids; D000838:Anions; D004952:Esters; D008823:Micelles; D013501:Surface-Active Agents; D014874:Water Pollutants, Chemical; C030641:alkylbenzyl sulfonic acid