Reverse quantitative structure–activity relationship for modelling the sorption of esfenvalerate to dissolved organic matter: A multivariate approach

• Published in: Chemosphere (Oxford) 2002-12, Vol.49 (10), p.1317-1325
• Main Authors: Thomsen, Marianne, Dobel, Shima, Lassen, Pia, Carlsen, Lars, Bügel Mogensen, Betty, Erik Hansen, Poul
• Format: Article
• Language: English
• Subjects: Adsorption; Applied sciences; Biological and physicochemical phenomena; Dissolved and/or dispersed organic matter; Earth sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; Equilibrium partitioning coefficient; Esfenvalerate; Exact sciences and technology; Freshwater; Humic Substances; Insecticides - chemistry; KDOM; Models, Theoretical; Natural water pollution; Nitriles; Pollution; Pollution, environment geology; Pyrethrins - chemistry; Reverse QSAR; Solubility; Structure-Activity Relationship; Water treatment and pollution
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/S0045-6535(02)00510-6

The sorption of the pyrethroid, esfenvalerate, to the dissolved and/or dispersed fraction of eight different natural humic compounds has been investigated. The dissolved organic matters (DOMs) included in this study originate from ground water, soil pore water, and surface waters. Sorption was modelled at DOM concentration levels where equilibrium partitioning of esfenvalerate between DOM and the aqueous bulk phase prevails. The inherent characteristics of the eight different humic materials, quantified in the preceding paper by Thomsen et al. (2002, this issue (PII: S0045-6535(02)00335-1)), have been used as explanatory variables for modelling this equilibrium partitioning. Using a reverse QSAR approach based on by projection-into-latent-structure regression (PLS-R) inherent sorbent properties determining for the sorption affinity of esfenvalerate to DOM were analysed. For all humic substances a decrease in the DOM-normalised equilibrium-partitioning coefficient, K DOM, with increasing concentration of DOM was observed. Significant variations in K DOM values, as function of the inherent characteristics of the individual humic substances, were found at DOM concentrations of 75 and 100 ppm, respectively. The latter is a strong indication of variations in sorption mechanisms of esfenvalerate to DOM of varying inherent properties. Groupings in the principal property space quantifying DOMs may indicate that separate models are needed for quantifying the equilibrium partitioning to different classes of DOM.