In the Antarctic continent, snow and ice are fundamental in the study of the input mechanism of transferring pollutants originating from distant areas through the atmospheres. Various persistent organic pollutants (POPs) and other potential terrestrial biomarkers have been investigated, in particular polycyclic aromatic hydrocarbons (PAHs), pesticides, polychloro biphenyls, polyfluoroalkyl substances (PFASs), polybrominated diphenyl ethers (PBDEs) and polychlorinated dibenzo-p-dioxins and furans. Moreover, during long-range atmospheric transport and after deposition, pollutants may undergo photodegradation and transformation processes (e.g., by microorganisms), and some reaction products could be even more toxic than their parent compounds. Thus, the first objective of this research will be the development of an analytical platform based on liquid chromatography-high resolution mass spectrometry (LC-HRMS) for the determination of the main emerging contaminants, such as PFASs, PBDEs and OH-PAHs, together with their degradation/transformation products, including new/unexpected compounds.
Another important component of Antarctic environment is the dissolved organic matter (DOM), constituted by several thousand compounds. Molecular fingerprints of snowpack DOM indicate that it has both natural and anthropogenic origin. Therefore, the knowledge of DOM composition could provide useful information about pollutants transport, but primarily on bacteria, algae and other microorganisms. Due to its complexity and heterogeneity, DOM characterization is an analytical challenge, since its composition also derives from various and sometimes unknown bacteria/organisms. Thus, the second objective of this project will be the development of an analytical strategy based on LC-HRMS for snow DOM molecular characterization, with attention to both small molecules (untargeted metabolomics approach) and proteins, searched also on the snow filtrate (bottom-up, metaproteomics approach).
