Analytical methods based on gas chromatography mass spectrometry for the analysis of emerging contaminants: UV filters, bisphenols, and microplastics

This thesis presents the development and optimization of GC-MS, GC-MS/MS, and Py-GC-MS) for the detection of UV filters, bisphenols, and microplastics in environmental waters and in vitro models. Given the growing environmental concerns and their human exposure associated with these contaminants, particularly their persistence and impact on ecosystems and human health, this study employed cutting edge, solid phase extraction and solid phase microextraction techniques and chromatographic methods to address these challenges. The thesis structured into three main topics, each dedicated to a specific class of emerging contaminants. The first topic explored UV filters, specifically their detection and quantification by SPE and GC-MS/MS in Adriatic seawaters, providing insights into their environmental distribution and concentration. Among UV filters, the thesis further investigated the isomerization product of EHMC (ethylhexyl methoxycinnamate), a commonly used UV filter, evaluating its phototransformation process under natural and simulated conditions by HS-SPME and GC-MS. In vitro studies on skin models and water matrices helped clarify their behavior and potential risks. The second topic focused on bisphenol A (BPA) and its analogues, which are widely used in plastics and consumer products. The research investigated the environmental fate and persistence of these compounds. An organic-solventless procedure using in-vial acetylation SPME was developed and employed to enhance the detection and quantification of bisphenol in various environmental waters. This method allows for improved sensitivity and precision in monitoring bisphenols at trace levels in complex environmental matrices, providing valuable data on their persistence and potential risks to aquatic ecosystems. Thirdly, analytical pyrolysis (Py-GC-MS) was applied to estimate the presence of added polyethylene and polystyrene in an in vitro human colon model system during the duration of the fermentation experiment. A sample pretreatment was adopted based on Fenton oxidation. The results confirmed microplastic presence and highlighted analytical challenges in complex organic matrices.