Non-targeted screening analysis (NTS) based on high-resolution mass spectrometry (HRMS) is a novel holistic approach, for obtaining information on the chemical fingerprint of an environmental sample. This project is a systematic qualitative and quantitative validation study; identifying which chemical substances on a defined suspect list can be analyzed on which analytical NTS platforms and down to which concentration level in a groundwater sample. A suspect list of 967 xenobiotics was constructed to contain environmental pollutants of special concern (MFS) for the aquatic environment. Analysis of standard mixtures containing the 967 chemicals showed that in combination, five NTS platforms were able to detect 70% of the studied chemical space (679 chemicals). The combination of three of the platforms; nLC-ESI(+)-HRMS, AEC-ESI(-)-HRMS and GC-EI(+)-HRMS covered 66% of the studied compounds. Twelve 2 L grab samples of groundwater were collected from one DGU well. Six samples were collected in glass containers and six in HDPE containers. Two samples in each container type was either left unspiked, pre-spiked (before pre-concentration) or post-spiked with the 967 chemical substances: 84% of the 679 chemical compounds detectable on the platforms were recovered on a 0.1 μg/L spike-level. The limit of detections (LOD) for most substances were below 0.04 μg/L. The results show that the combination of different NTS platforms is necessary to ensure that a broad chemical range is included in future NTS methodologies. Certain types of chemicals were identified as not being resolved in this NTS methodology
