Curating “Suspect Lists” for International Non-target Screening Efforts
Emma L. Schymanski, Reza Aalizadeh, Nikolaos S. Thomaidis, Juliane Hollender, Jaroslav Slobodnik, Antony J. Williams5
1Luxembourg Centre for Systems Biomedicine (LCSB), University of Luxembourg, Campus Belval, Luxembourg.
2National and Kapodistrian University of Athens, Department of Chemistry, Panepistimiopolis Zografou, 157 71 Athens, Greece.
3Eawag: Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland.
4Environmental Institute, Okružná 784/42, 972 41 Koš, Slovak Republic.
5National Center for Computational Toxicology, US EPA, Research Triangle Park, Durham, NC, USA.
PRESENTED by Emma Schymanski
The NORMAN Network (www.norman-network.com) is a unique network of reference laboratories, research centres and related organisations for monitoring of emerging environmental substances, through European and across the world. Key activities of the network include prioritization of emerging substances and non-target screening. A recent collaborative trial revealed that suspect screening (using specific lists of chemicals to find “known unknowns”) was a very common and efficient way to expedite non-target screening (Schymanski et al. 2015, DOI: 10.1007/s00216-015-8681-7). As a result, the NORMAN Suspect Exchange was founded (http://www.norman-network.com/?q=node/236) and members were encouraged to submit their suspect lists. To date 20 lists of highly varying substance numbers (between 52 and 30,418), quality and information content have been uploaded, including valuable information previously unavailable to the public. All preparation and curation was done within the network using open access cheminformatics toolkits. Additionally, members expressed a desire for one merged list (“SusDat”). However, as a small network with very limited resources (member contributions only), the burden of curating and merging these lists into a high quality, curated dataset went beyond the capacity and expertise of the network. In 2017 the NORMAN Suspect Exchange and US EPA CompTox Chemistry Dashboard (https://comptox.epa.gov/) pooled resources in curating and uploading these lists to the Dashboard (https://comptox.epa.gov/dashboard/chemical_lists). This talk will cover the curation and annotation of the lists with unique identifiers (known as DTXSIDs), plus the advantages and drawbacks of these for NORMAN (e.g. creating a registration/resource inter-dependence). It will cover the use of “MS-ready structure forms” with chemical substances provided in the form observed by the mass spectrometer (e.g. desalted, as separate components of mixtures) and how these efforts will support other NORMAN activities. Finally, limitations of existing cheminformatics approaches and future ideas for extending this work will be covered. Note: This abstract does not reflect US EPA policy.