title: Retention of selected steroids on a silt-loam soil.
abstract: This study used batch-equilibrium techniques to evaluate the soil sorption and desorption of target steroids, representative of the estrogen, androgen, progestogen and corticosteroid families. The sorption kinetics exhibited an immediate rapid sorption followed by a slow process with a duration dependent on soil particle size. Adsorption and desorption isotherms could be described by the Freundlich equation, in a non-linear form (1/n < 1). High organic carbon-water partitioning coefficient (K(OC)) values indicate that a large mass fraction of the hormones will be associated with the sorbed phase. As a result of the poor linear correlation between log K(OC) and log K(OW) (octanol-water partition coefficient), it could be assumed that both hydrophobic and hydrogen bonding interactions contribute to the sorption mechanisms of the selected steroids. A hysteresis phenomenon was observed, varying with particle size, indicating strong irreversible interactions between some steroids and soil.
authors.affiliation: Université Lyon, Institut des Sciences Analytiques, Département Service Central d'Analyse, CNRS, Equipe TRACES, Villeurbanne, France.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Gineys
authors.forename: Barbara
authors.initials: B
authors.lastname: Giroud
authors.forename: Mickael
authors.initials: M
authors.lastname: Gineys
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Vulliet
mesh_terms: D000327:Adsorption; D012989:Soil Pollutants / Q000737:chemistry*; D013256:Steroids / Q000737:chemistry*
chemical_list: D012989:Soil Pollutants; D013256:Steroids