Revisiting Five Years of CASMI Contests with EPA Identification Tools

Area of Science:

• Analytical Chemistry
• Environmental Science
• Computational Chemistry

Background:

• High-resolution mass spectrometry (HRMS) is crucial for non-targeted analysis (NTA).
• Evaluating software for chemical identification in NTA is challenging due to diverse tools.
• The Critical Assessment of Small Molecule Identification (CASMI) contests provide standardized MS/MS data for tool evaluation.

Purpose of the Study:

• To evaluate the performance of the US EPA's CompTox Chemicals Dashboard for chemical identification in HRMS-based NTA.
• To compare the Dashboard's capabilities against other tools using historical CASMI contest data.
• To assess the utility of the Dashboard's data and tools for NTA practitioners.

Main Methods:

• Utilized five historical CASMI contest datasets for compound identification.
• Employed the CompTox Chemicals Dashboard's tools and data within a spectral matching workflow.
• Accessed and processed CASMI data via the CASMI webpage.
• Reviewed and made available the CASMI structure sets through the Dashboard.

Main Results:

• The CompTox Chemicals Dashboard workflow performed competitively with tools used in previous CASMI contests.
• The Dashboard workflow ranked more challenge compounds in the top five than winners in three CASMI years and tied in a fourth.
• Reviewed CASMI structure sets are now accessible via the CompTox Chemicals Dashboard.

Conclusions:

• The CompTox Chemicals Dashboard demonstrates significant potential for enhancing chemical identification in HRMS-based NTA.
• Dashboard data and tools offer a valuable resource for NTA practitioners.
• The Dashboard's performance suggests its suitability for critical chemical identification tasks.