Non-target and suspect characterisation of organic chemicals of emerging concern in air and biota.
Publikasjon: Non-target and suspect characterisation of organic chemicals of emerging concern in air and biota.
Utgiver: Norwegian University of Life Sciences, Ås, Norway
Persistent organic pollutants (POPs) and other regulated organic chemicals are being monitored in the environment to evaluate the effectiveness of regulations and conventions, spatial and temporal trends as well as a compounds environmental fate. However, there are hundreds of thousands of chemicals in commerce and new chemicals are continuously being developed. Some of these new chemicals have similar physical-chemical properties as known POPs or regulated chemicals, but their environmental fate is not well documented. Therefore, it is important to screen environmental samples for new potential chemicals of emerging concern (CECs) to detect such CECs at an early stage, preferably before reaching toxic or harmful concentrations for humans and/or the environment. The scientific work of this thesis aims to provide new methods to screen simultaneously for large number of compounds within a wide range of polarity and to identify new potential CECs in air and biota. One specific aim of the research of this thesis was the development and evaluation of new clean-up methods omitting the use of destructive or very selective clean-up processes in order to keep as many as possible compounds of interest in the clean extract. For high-volume air samples a three-layer liquid chromatography method was established. For biota, this new clean-up method was combined with additional wide scope clean-up steps due to the complexity of biological samples. The evaluation of the new clean-up method found that it could provide sample extracts of similar cleanness and quality, compared to the traditional method using concentrated sulphuric acid, but also including a broader range of compounds (i.e. also acid-labile compounds). Another aim of the research was the development of data processing workflows for the detection, identification and prioritisation of new potential CECs as well as the development of a wide-scope instrumental method for comprehensive two-dimensional gas chromatography (GC×GC) combined with low-resolution mass spectrometry (LRMS). The combination of new clean-up methods, comprehensive detection methods, and new data processing workflows, could reveal several new potential CECs in air and biota which were detected for the very first time. It was found that some of the CECs detected in air may undergo long-range atmospheric transport, due to the detection in southern Norway and the Arctic. Furthermore, it was found that some of the detected CECs in biota may have a bioaccumulation potential. This highlights the importance of screening studies for the early detection of new CECs in the environment. Further research is necessary to evaluate the environmental fate of these found CECs for possible regulatory actions.