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Using the US EPA’s CompTox Chemistry Dashboard to advance non-targeted analysis and exposure research
Citation:
McEachran, A., J. Grossman, S. Newton, K. Isaacs, K. Phillips, N. Baker, Chris Grulke, J. Sobus, AND A. Williams. Using the US EPA’s CompTox Chemistry Dashboard to advance non-targeted analysis and exposure research. Presented at ISES 27th Annual Meeting, Research Triangle Park, NC, October 15 - 19, 2017. https://doi.org/10.23645/epacomptox.6807404
Impact/Purpose:
Abstract for presentation at the ISES meeting. The use of high resolution mass spectrometry (HRMS) and non-targeted analyses (NTA) is advancing exposure science by enabling researchers to more completely define the exposome. The aim of our research is to generate and implement an identification tool and workflow for NTA within the US EPA’s CompTox Chemistry Dashboard.
Description:
The use of high resolution mass spectrometry (HRMS) and non-targeted analyses (NTA) is advancing exposure science by enabling researchers to more completely define the exposome. However, confident structure identification of unknowns in NTA continues to present challenges to analytical chemists. Identification requires the integration of complementary data types to generate confident consensus structures; these data include the use of reference databases and source ranking algorithms, fragmentation prediction tools, and retention time prediction. The aim of our research is to generate and implement an identification tool and workflow for NTA within the US EPA’s CompTox Chemistry Dashboard (https://comptox.epa.gov), a chemistry resource and web application containing chemistry data on ~750,000 substances. Data for chemical identification were incorporated from a variety of sources, including: functional use prediction models, PubMed references, and environmental media occurrence models. Data were assembled and a scoring-based identification scheme was empirically developed such that true positives were identified at the top of candidate chemical lists. This scheme was evaluated using two test sets: a known test set of chemicals and a blinded, unknown mixture. This scoring method for tentative and probable identification of unknowns resulted in increased identification performance over previous workflows. We will discuss development of a visualization tool within the Chemistry Dashboard where users can visualize the relative contributions of identification-specific metrics on a list of candidate structures. The scoring-based method and visualization tools indicate the capability of NTA structure identification within the Dashboard and provide an open, accessible tool for exposure scientists and mass spectrometrists. This abstract does not necessarily represent the views or policies of the U.S. Environmental Protection Agency.
URLs/Downloads:
DOI: Using the US EPA’s CompTox Chemistry Dashboard to advance non-targeted analysis and exposure research
MCEACHRAN ISES_CLEARED.PDF (PDF, NA pp, 1162.225 KB, about PDF)