Abstract:

The aim of this work is to shown the research that we are carrying out at University of Cadiz regarding the identification of new organic contaminants in coastal marine systems and the study of their reactivity and final fate. Our research has basically three different aspects:

- Developing new methodologies for the identification and quantification of organic contaminants in marine samples: we use different techniques for the extraction and isolation of target compounds from aqueous (e.g., solid phase extraction, stir bar sorptive extraction) and solid matrices (e.g., pressurized liquid extraction, ultrasonic extraction). Analysis of chemicals is usually carried out by liquid chromatography or gas chromatography coupled to mass spectrometry (ion trap, triple quadrupole or time of flight detectors).

- Carrying out sampling campaigns to determine the concentrations and distribution of organic contaminants in coastal areas: we carry out regular sampling campaigns along the Spanish coast in order to monitor the presence of a wide range of organic contaminants, including polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), several families of pesticides, anionic and non-ionic surfactants (e.g., linear alkylbenzene sulfonates, nonylphenol ethoxylates, polyethylene glycols), personal care products (e.g., antimicrobials, fragrances, UV filters) and pharmaceuticals (e.g., anti-inflammatories, psychiatric drugs, antibiotics, lipid regulators). We take not only surface water samples, but also sediment cores (which we date using 137Cs and 210Pb), and we have started deploying passive samplers (PDMS and POCIS).

- Running laboratory experiments to characterize the processes affecting the behavior of a chemical in the environment: we perform a series of experiments mostly for every new compound that we detect in the marine environment. These assays are intended to know sorption-desorption capacity of organic chemicals, their degradability (not only aerobic degradation tests using seawater are performed but we also study anaerobic degradation in sediments as well as photodegradation in the water column) and if they show any bioaccumulation potential. This last kind of experiments is carried out using a flow through system and several marine species such as clams and flatfish, allowing to calculate the bioconcentration factor and to monitor changes in enzymes and any metabolite (metabolomics).