Open Access

One of the consequences of the manifold uses of various organic substances in households, agriculture, and industry is that these can eventually end up in the aquatic environment. Each of these anthropogenic substances represents a potential harmful contamination for the different water resources. Therefore, a constant and comprehensive monitoring of organic trace substances in the resources used for drinking water treatment is essential to protect of the quality of drinking water. In addition to the commonly used target screening, the non-target screening with high performance liquid chromatography-mass spectrometry (HPLC-MS) has gained in importance in recent years and became a useful tool for the monitoring of organic trace substances in water This work describes new strategies for the screening and identification of unexpected or unknown organic trace substances in water. The approaches consider all compounds detectable by the used analytical method for further data evaluation. That is the fundamental meaning of non-target screening. However, focusing on relevant contaminants during the screening process is required as large numbers of substances are being detected for each sample. Consequently, a sample is not regarded as an isolated specimen, but rather evaluated in relation to a set of other samples based on considerations of their temporal, spatial, or process-related connections. The efficiency of the different developed strategies were demonstrated successfully for the identification of unknown contaminants in monitoring samples of different water resources as well as for the screening and structural elucidation of ozonation by-products of known contaminants (4- and 5-methyl-1H-benzotriazole) of the Danube water. In addition, to effectively support the identification of compounds, the concept of the DAIOS (Database-Assisted Identification of Organic Substances) was introduced. The new described strategies for the screening and identification of organic trace substances in water opens the possibilities of various other applications in environmental analysis, for example in the environmental remediation of contaminated sites, as well as for the evaluation of the process steps during drinking and waste water treatment.