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(15-27) The sea surface microlayer: A sampling challenge for organic contaminants. García, Núria1, Guitart, Carlos, ABSTRACT- Sea surface microlayer (SML) has been identified as an important medium for the enrichment of persistent organic pollutants at the air-water interface and a key compartment in their biogeochemical cycles. However, sampling procedures are sometimes troublesome due to the nature of the SML and to the fact that different sampling devices collect different thicknesses, thus providing diverse results. In the present work, several sampling methods such as the Garret metal screen, the Harvey glass plate and roller, and a floating bottle were used and compared in terms of concentrations and enrichment factors for a wide range of dissolved, colloidal and particulate organic contaminants. PCBs, PAHs, LAS and alkylphenols were determined in two coastal areas of the western Mediterranean, one heavily impacted (offshore Barcelona, Spain) and another considered pristine (Banyuls, France). The results were compared to underlying waters providing relevant information on the role of SML as an enrichment medium for hydrophobic contaminants at different thickness scales (60 mm to 2-3 mm). The distinct chemical properties, composition and structure of SML versus underlying water suggests that SMLs should be taken into account in multimedia models addressing the fate and global transport of persistent organic contaminants. Key words: PCBs, PAHs, Nonylphenols, Surface microlayer |
balos, Manuela1, Dachs, Jordi1, Bayona, Josep*,1, Albaigés, Joan1, 1 Jordi Girona, 18, Barcelona, Spain