AbstractsChemistry

The flux of emerging organic contaminants into environment is a global threat, which is widely studied and monitored. However, current regulation is not able to keep up with the increasing variety of new compounds released to the environment. More efficient and comprehensive analytical methodologies are required to enable sufficient monitoring of these compounds for legislative purposes. Non-targeted analytical approaches are able to identify previously unknown contaminants, which is not possible with conventional targeted methods. Therefore, the development of novel non-target methodologies is important. The goal of the thesis was to look for new ways to utilize non-targeted data for environmental applications with a special emphasis on wastewater analysis. The developed methodologies focused on chemometric quantification of non-target compounds, identification of steroidal transformation products, statistical cross-sample analysis of wastewater and atmospheric particles as well as non-targeted approaches to quantify selectivity of adsorbents employed in sample preparation. The samples were analyzed by comprehensive two-dimensional gas chromatography ‒ time-of-flight mass spectrometry utilizing mass spectral libraries and retention indices for compound identification. Different solid-phase extraction procedures were applied to aqueous samples, and ultra-sound assisted extraction to solid samples. The study included also the synthesis of novel polymeric adsorbents with increased selectivity towards steroidal compounds. Modern statistical software was utilized for data handling and chemometrics. The multidimensional system enabled the analysis of complex wastewater samples, and several steroids and their transformation products were identified from the samples. It was concluded that hydrophobic steroids were efficiently removed from wastewater by adsorption to sewage sludge. However, elimination from sludge was less efficient and steroids were also found in the processed sludge destined for agricultural purposes. The chemometric model for the prediction of concentrations of non-target compounds with steroidal structure demonstrated good accuracy. Non-targeted approaches allowed the arithmetic comparison of adsorbent selectivity, when previously only relative methods have been used. Fast comparison of different wastewater and aerosol samples was possible through cross-sample analysis with non-targeted data. Non-targeted approaches presented in this thesis can also be applied to other groups of contaminants and thus promote the available knowledge about environmental pollution. New ways to utilize non-targeted methodologies and cross-sample analyses demonstrated their value in this thesis and hopefully inspire future studies in the field. Orgaanisten haitta-aineiden kerääntyminen ympäristöön on laajalti tutkittu globaali ongelma. Näiden yhdisteiden seuraaminen ja sääntely on kuitenkin hankalaa, koska lainsäädäntö on hitaampaa kuin uusien kemikaalien kehittäminen. Tämän takia tarvitaan tehokkaampia ja…