Analytical Validation of a Portable Mass Spectrometer Featuring Interchangeable, Ambient Ionization Sources for High Throughput Forensic Evidence Screening

• NCJ Number: 252301
• Author(s): Zachary E. Lawton, Angelica Traub, William L. Fatigante, Jose Mancias, Adam L. O'Leary, Seth E. Hall, Jamie R. Wieland, Herbert Oberacher, Michael C. Gizzi, Christopher C. Mulligan
• Date Published: June 2017
• Length: 12 pages
• Agencies: NIJ-Sponsored
• Award: Accessing the Probative Value of Physical Evidence at Crimes Scenes with Ambient Mass Spectrometry and Portable Instrumentation; Analytical Validation and Impact Assessment of On-Site Evidence Screening via Ambient Sampling, Portable Mass Spectrometry

Annotation

Since forensic evidentiary backlogs are indicative of the growing need for cost-effective, high-throughput instrumental methods, this article profiles one such emerging technology that shows high promise in meeting this demand while also allowing on-site forensic investigation; namely, portable mass spectrometric (MS) instrumentation, particularly that which enables the coupling to ambient ionization techniques.

Abstract

Although the benefits of rapid, on-site screening of contraband can be anticipated, the inherent legal implications of field-collected data require that the analytical performance of technology used be commensurate with accepted techniques. To this end, comprehensive analytical validation studies are required before broad incorporation by forensic practitioners can be considered. This is the focus of this work. Pertinent performance characteristics such as throughput, selectivity, accuracy/precision, method robustness, and ruggedness have been investigated. Reliability in the form of false positive/negative response rates have also been assessed, examining the effect of variables such as user training and experience level. To provide flexibility toward broad chemical evidence analysis, a suite of rapidly-interchangeable ion sources has been developed and characterized through the analysis of common illicit chemicals and emerging threats like substituted phenethylamines. (Publisher abstract modified)