ANALYTICAL APPROACHES FOR THE ENVIRONMENTAL CHARACTERIZATION AND RISK ASSESSMENT OF MARINE SEDIMENTS

The present doctoral thesis was developed within the framework of the PhD program in Chemical and Pharmaceutical Sciences and Biotechnology at the University of Camerino, focusing on the application of analytical chemistry to marine environmental monitoring. The research arises from the growing necessity to understand and mitigate the impact of anthropogenic pressures on fragile coastal ecosystems, with particular attention to the Tremiti Islands Marine Protected Area (Adriatic Sea, Italy). The thesis is primarily structured as a collection of scientific articles that have been published, which constitute the core of the experimental and interpretative work. The work is structured to provide both a methodological and an environmental perspective, integrating analytical chemistry, environmental geochemistry, and chemometrics. The overall aim is to develop and apply advanced analytical procedures capable of assessing contamination levels, ecological risks, and biological responses in marine ecosystems. Chapter 1 provides a general introduction to the research background and objectives. It outlines the ecological significance of Posidonia oceanica meadows and marine sediments as environmental indicators and discusses the analytical challenges involved in quantifying trace metals in complex matrices. Chapter 2 describes analytical framework adopted in this research that integrates standardized sampling procedures, validated laboratory methodologies and multivariate statistical tools to investigate the chemical composition, geochemical behavior and biological responses of marine environmental matrices. Although each experimental chapter (3.1–3.3) presents its specific workflows, the present chapter provides an overarching methodological foundation covering sampling strategies, instrumental techniques, quality assurance protocols and data-treatment procedures. Chapter 3 constitutes the experimental core of the thesis and is divided into (i) Comparative evaluation of pre-treatment techniques for the analysis of marine sediments, focuses on the optimization of digestion procedures to ensure reliable quantification of trace metals; (ii) Analysis and evaluation of Posidonia oceanica’s stress factors in the marine environment of Tremiti Island, examines the physiological responses of P. oceanica to environmental stressors through the analysis of metals, biogenic volatile organic compounds (BVOCs), and oxidative stress markers (DMSP/DMSO ratio); (iii) Exploring Environmental Metal Monitoring Data Using Chemometric Techniques, applies multivariate statistical and chemometric tools to interpret complex environmental datasets and to correlate chemical parameters with biological indicators; (iv) Assessment of the Geochemical Availability and Ecological Risk of Trace Metals in Marine Sediments of the Tremiti Islands, provides a detailed geochemical and ecological risk assessment based on sequential extraction, mineralogical characterization, and pollution indices. Chapter 4 summarizes the main findings, highlighting the methodological advancements achieved and their implications for marine environmental management. The conclusions emphasize the importance of combining analytical innovation, data science, and ecological interpretation to achieve a holistic understanding of marine ecosystem health. Overall, this thesis represents an interdisciplinary effort to bridge analytical chemistry and environmental science, offering new methodological tools and interpretative strategies for assessing contamination dynamics and ecological risk in Mediterranean coastal ecosystems.