Studio della contaminazione da IPA del riccio di mare Paracentrotus Lividus in Sardegna

The goal of this work of thesis is to building a pratical method to be used for testing and monitoring the chemical pollution of restricted marine areas. The sea urchin Paracentrotus Lividus (Lamarck - 1816) was the biomarker adopted for this study. This echinoderm, usually present in the shallow coastal water of the Mediterranean sea, is basically herbivorous but can feed on many other organisms like plankton and all marine food falling down in the bentonic area of the coastal sea. Unlike mussels wich filter water it feeds mainly on micro and macroalgae and is not influenced by the sea tide, so it is a reliable instrument to performing analytical checks about local pollutions of coastal areas. To extract from the matrix and analyze the sea urchin’s roes, or better is to say male and female “gonads”, was built a modified “QuEChERS” method (Quick, Easy, Cheap, Rugged and Safe), based on dSPE (dispersive Solid Phase Extraction) instead of SPE (Solid Phase Extraction) as usually performed earlier. The extraction was performed by using only two centrifuge tubes with a little quantity of solvent, avoiding previous separation of fat acids from matrix and isolation phases of the pollutant compounds by gel packed columns and with consumption of a big quantity of solvents. Were investigated to this purpose 17 polycyclic haromatic hydrocarbons in gonads of Paracentrotus Lividus sea urchin. Was performed a validation of the method determining instrument limit of detection (LOD) and quantification (LOQ), recovery, precision and linearity. Were determinated good parameters with LOD under 1,5 μg/kg and LOQ under 5 μg/kg for all PAH, in agreement with quality criteria of Commission Regulation (EC) n° 333/2007. The recovery ranges were from 72 to 119 %, with RSD ranging from 3 to 17 % in the worst case. Precision and linearity were in accordance with EC SANCO/10684/2009 values. Lipophilic Polycyclic aromatic Carbons were investigated from two Sardinian areas: “Capo Pecora” in west Sardinian coast with low agricultural, industrial and antropic density area, and “Capitana”, with high antropic density.The sea urchins were from rocky sea bottom and from meadows of “Posidonia Oceanica”, a marine sea grass most frequently present in the Mediterranean sea. Many of these pollutants were determined in the gonads of the two areas showing a general ubiquity beginning from the PAH’s with a low number of rings to more heavy pollutants. It’s not hazardous affirm that this work of thesis has been an important step to performing analysis of the PAH’s in sea urchin’s gonads and to use this marine animals as reliable biomarkers on detecting and monitoring the contamination of restricted areas of coastal regions.