Collaborative Development of a Data Interpretation Tool for DART-MS Analysis

Description:
The forensics community has seen increased adoption and implementation of ambient ionization mass spectrometry (AI-MS) techniques in recent years due to their ability to provide rapid, high-quality, chemical information with minimal to no sample preparation. These approaches are often touted to speed up analysis times due to limited sample preparation and lack of chromatography. However, this also leads to complicated mass spectral data with limited software tools to assist in data analysis.

To address the need for better data interpretation capabilities, we have developed an open-source software tool that is specifically designed for data produced by direct analysis in real time mass spectrometry (DART-MS) and other AI-MS approaches. The DART-MS Data Interpretation Tool (DIT) allows users to presumptively identify compounds from a mixture mass spectrum through comparisons to the NIST DART-MS Forensics Database. Using the Inverted Library Search Algorithm (ILSA), compounds are identified and similarity scores are calculated. The ILSA and the DIT can leverage multiple in-source collision induced dissociation (is-CID) spectra to provide more discriminating identifications by accounting for both molecular ion and fragment ion information. Most importantly, development of the DIT was done in collaboration with a group of practicing forensic laboratories – who provided invaluable feedback on usability, functionality, and requirements – to ensure the software met the needs of the community.

This presentation will discuss the core functionalities and features of the DIT – mass spectral searching, spectral database searching, and reporting – and their development via collaboration with the community. A look into the creation and evaluation of the ILSA, which underpins the DIT, will be provided. Current efforts to simplify AI-MS data interpretation in other areas of forensics, and efforts to make the DIT usable to a broader set of stakeholders, will also be highlighted.

Speaker: Edward Sisco - National Institute of Standards and Technology
Edward Sisco is a research chemist at NIST whose focus is on the development of tools and methodologies to address forensic chemistry measurement challenges. His research in the field of seized drugs includes development of DART-MS methods and tools, new approaches to GC-MS optimization analysis, visualizing and measurement drug background levels in laboratories, and assisting practicing laboratories with implementation of new technology. He is a member of AAFS, ASTM, and OSAC.