Occurrence and distribution of linear alkylbenzene sulfonates and sulfophenylcarboxylic acids in several Iberian littoral ecosystems.

The distribution of linear alkylbenzene sulfonates (LAS) and sulfophenylcarboxylic acids (SPC) has been characterized in water and sediment of five Iberian estuaries and a saltmarsh channel. The highest concentrations of LAS and SPC were detected in shallow zones close to discharge points of untreated urban effluent, and decreased sharply with increasing distance from these. SPC homologues of between 3 and 12 carbon atoms were detected, although their concentrations were several orders of magnitude lower than the corresponding LAS. The highest SPC concentrations found were of medium carboxylic chain lengths (C6-C8) in water, and of longer chain lengths (C9-C11) in particulate material. LAS homologues were associated preferentially with the particulate material. The vertical distribution of LAS in the water column was not homogeneous, in contrast to that presented by the SPC homologues. In the case of the Sancti Petri Channel, there was a net flow of LAS exportation into the Bay of Cádiz, of -38.6 kg day(-1), and a net flow for SPC of -6.0 kg day(-1). The daily mass input of LAS and their biodegradation intermediates from the Sancti Petri Channel to Cadiz Bay was 44.6 kg.