PRESENTATION ACS SPRING 2018: Using the US EPA’s CompTox Chemistry Dashboard for structure identification and non-targeted analyses

25 Mar

Using the US EPA’s CompTox Chemistry Dashboard for structure identification and non-targeted analyses

Antony J. Williams, Andrew D. McEachran, Seth Newton, Kristin Isaacs, Katherine Phillips, Nancy Baker, Christopher Grulke and Jon R. Sobus

High resolution mass spectrometry (HRMS) and non-targeted analysis (NTA) are advancing the identification of emerging contaminants in environmental matrices, improving the means by which exposure analyses can be conducted. However, confidence in structure identification of unknowns in NTA presents challenges to analytical chemists. Structure identification requires integration of complementary data types such as reference databases, fragmentation prediction tools, and retention time prediction models. The goal of this research is to optimize and implement structure identification functionality within the US EPA’s CompTox Chemistry Dashboard, an open chemistry resource and web application containing data for ~760,000 substances. Rank-ordering the number of sources associated with chemical records within the Dashboard (Data Source Ranking) improves the identification of unknowns by bringing the most likely candidate structures to the top of a search results list. Database searching has been further optimized with the generation of MS-Ready Structures. MS-Ready structures are de-salted, stripped of stereochemistry, and mixture separated to replicate the form of a chemical observed via HRMS. Functionality to conduct batch searching of molecular formulae and monoisotopic masses was designed and released to improve searching efforts. Finally, a scoring-based identification scheme was developed, optimized, and surfaced via the Dashboard using multiple data streams contained within the database underlying the Dashboard. The scoring-based identification scheme improved the identification of unknowns over previous efforts using data source ranking alone. Combining these steps within an open chemistry resource provides a freely available software tool for structure identification and NTA. This abstract does not necessarily represent the views or policies of the U.S. Environmental Protection Agency.


About tony

Founder of ChemZoo Inc., the host of ChemSpider ( ChemSpider is an open access online database of chemical structures and property transaction based services to enable chemists around the world to data mine chemistry databases. The Royal Society of Chemistry acquired ChemSpider in May 2009. Presently working as a consortium member of the OpenPHACTS IMI project ( This focuses on how drug discovery can utilize semantic technologies to improve decision making and brings together 22 European team members to develop an infrastructure to link together public and private data for the drug discovery community. I am also involved with the PharmaSea FP7 project ( trying to identify new classes of marine natural products with potential pharmacological activity. I am also one of the hosts for three wikis for Science: ScientistsDB, SciMobileApps and SciDBs. Over the past decade I held many responsibilities including the direction of the development of scientific software applications for spectroscopy and general chemistry, directing marketing efforts, sales and business development collaborations for the company. Eight years experience of analytical laboratory leadership and management. Experienced in experimental techniques, implementation of new NMR technologies, walk-up facility management, research and development, manufacturing support and teaching. Ability to provide situation analysis, creative solutions and establish good working relationships. Prolific author with over a 150 peer-reviewed scientific publications, 3 patents and over 300 public presentations. Specialties Leadership in the domain of free access Chemistry, Product and project management, Organizational and Leadership development, Competitive analysis and Business Development, Entrepreneurial.
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Posted by on March 25, 2018 in ACS Meetings


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