Aplicación de materiales mesoporosos a la preconcentración de contaminantes orgánicos en aguas, y su determinación mediante cromatografía líquida de alta resolución y espectrometría de masas

Resumen

Water scarcity represents a growing threat to the global economy and perhaps humanity's survival. The increase and severity of the drought, enhanced by Climate Change, the uncontrolled use of water both on a large scale (industry and agriculture) and on a small scale (households), and pollution are the leading causes of the great scarcity of water worldwide, making its use more and more restricted and unaffordable for a more significant number of people. Currently, according to data published by the World Resources Institute (WRI), more than 1 billion people live in areas with water shortages. If the situation does not change, by 2025, the number of people could reach a total of 3.5 billion. The most affected countries are in the Middle East, North Africa and Southern Europe, such as Spain. In Europe, more than a third of the water is used in agricultural practices. In the coming years, significant losses in groundwater recharge are expected, which will have detrimental consequences for the ecosystem and irrigation water supplies. Droughts will become increasingly common in the Mediterranean, causing water shortages and a decrease in hydroelectric potential, which will affect the economy of these countries, based mainly on agriculture. In this regard, intensive agriculture affects both water quantity and quality, being one of the leading causes of drinking water scarcity because it is a source of contamination by pesticides and fertilisers. However, in recent years the presence of other pollutants in water, potentially harmful to health, has become evident, called "emerging" pollutants. This group includes pharmaceuticals and some components used in personal care products, such as parabens and UV filters. Thus, the leading causes of drinking water scarcity are: 1. Population growth. 2. Contamination of surface and groundwater, which has expanded at the same time as industrial expansion. 3. Increasing demand for water. This PhD project involves developing and evaluating mesoporous materials as sorbents for the solid phase extraction of organic contaminants from environmental waters of different nature and analysis by advanced analytical instruments. In general, the following stages can be distinguished in an analytical method: 1. Extraction. 2. Analytical separation and detection (identification and quantification). 3. Validation of the method at concentration levels according to the requirements of the Water Policy Legislation. The objective of the first stage was to evaluate the use of mesoporous materials, synthesized in the laboratory, as sorbents for the extraction of organic pollutants (priority and emerging) in environmental waters. In the second stage, the contaminants were separated, detected and quantified by liquid chromatography coupled to a triple quadrupole detector (LC-QqQ-MS/MS). Finally, the methods were validated following the International Validation Guidelines and applied to the analysis of parabens, UV filters and pesticides in surface and groundwater, which yielded outstanding results comparable to those obtained with conventional sorbents.