Application of Non-Target Analysis with LC-HRMS for the Monitoring of Raw and Potable Water: Strategy and Results: Assessing Transformation Products of Chemicals by Non-Target and Suspect Screening − Strategies and Workflows Volume 2

This contribution focuses on the application of non-target screening by liquid chromatography-high resolution mass spectrometry (LC-HRMS) as a tool in routine water analysis. From the perspective of water suppliers, comprehensive monitoring strategies are required to ensure good water quality. We will illustrate the strengths of the non-target approaches based on three chosen case studies. In principal, the non-target analysis enables monitoring approaches which also cover unknown or unexpected contaminants. The archive function of HRMS data comprises various benefits such as retrospective screening and also allows determining concentrations in a semi-quantitative way. Temporal prioritization in combination with multivariate statistics emerged as helpful strategy for the detection of new contaminants. This is exemplified for the identification of a spill event in river water. The spatial sampling information, on the other hand, allows the localization of possible sources of contamination. Prioritization based on the analytical request reduces thousands of signals to few interesting candidates which increases the success rate during the identification. By such measures, it was possible to prove that a groundwater contamination is caused by an industrial waste water treatment plant. For the evaluation of processes for water treatment, identification and quantification of individual contaminants is not always of major interest. However, sophisticated strategies are needed to compare the purification efficiency of new technologies to already established ones. Here we evaluated the effectiveness of the fourth treatment step based on activated carbon filtration in waste water treatment plants.