Resumen de Assessment of organic micropollutants in environmental and food samples by liquid chromatography-mass spectrometry: a spatiotemporal analysis
The presence of organic microcontaminants in the environment is an increasing problem that poses new and complex challenges for both human health and ecosystem integrity. Some of these chemical compounds can have significant impacts on terrestrial and aquatic biota, as well as potential risks to public health. Two of the most relevant sources responsible for releasing these contaminants into the environment are agricultural activities, due to the intensive use of plant protection products, and the discharge of urban wastewater that does not receive adequate treatment before being released into aquatic environments.
Despite several decades of research on the role of contaminants in the environment, additional information is still needed regarding their distribution, toxicity, and impact, not only of the parent compounds but also of their transformation products and excretion metabolites (as is the case of pharmaceuticals). Generating this information with a high degree of reliability, and at an affordable cost, requires the availability of robust and sensitive multi-analyte methodologies that ensure the determination of a wide range of microcontaminants in matrices with different properties.
In this context, one of the main objectives of this doctoral Thesis has been to develop analytical methodologies for the identification and quantification of organic microcontaminants in various environmental samples, such as wastewater, surface water, groundwater, sludge, soils and food products such as wine. In the specific case of environmental matrices (surface and wastewater, as well as sludge), the focus was placed on determining compounds of different origins (pharmaceuticals, personal care products, industrial additives), while in agricultural samples, the study focused on the determination of pesticide residues using target methods and screening protocols. In some specific cases involving chiral microcontaminants, in addition to determining the total concentrations of the compounds of interest, their enantiomeric fractions were also investigated. It is important to highlight that several of the compounds considered in this Thesis were, or have been, included in various lists of substances to be monitored in the aquatic environment, including the most recent revisions of the EU Watch Lists of contaminants to be monitored in aquatic environments, or in the list of compounds proposed for evaluating the effectiveness of domestic wastewater treatments.
To achieve this aim, the research presented in this Thesis was divided into two chapters, each one aligned with the proposed objectives.
Chapter I: Development of analytical methodologies for the determination of organic micropollutants in water samples.
This chapter presents and discusses the methodological advances achieved for the determination of organic micropollutants in various water matrices. By integrating solid-phase extraction techniques with liquid chromatography coupled to mass spectrometry, the studies included making a significant contribution to overcome the analytical challenges posed by the complex nature and low concentration levels of these compounds in environmental samples. These methodologies were applied to real samples, providing valuable insights into the environmental behaviour and potential risks associated with these substances.
Chapter II: Occurrence and risk assessment of micropollutants in different matrices.
The second chapter focuses on offering a comprehensive overview of the presence of pharmaceuticals and pesticides across diverse matrices, namely sludge, agricultural soils, wine, and various types of water. It discusses their analytical determination, observed occurrence patterns, and the related environmental and human health risks. This chapter includes the most outstanding results obtained under the VITICONTROL initiative, which focuses on assessing the environmental impact of intensive pesticide use in viticulture.
