ASTM E2677: Web-based International Standard on Limit of Detection for Explosive Trace Detectors (and More) - Opioids and Ozone
R M. Verkouteren, Nathanael A. Heckert, Stefan D. Leigh, Edward R. Sisco, James E. Norris, Jeffrey A. Lawrence, Amber Burns
The performance characteristics of explosive and narcotic trace detectors are mission-critical to agencies worldwide that are charged with protection of the public, defense for mass transit and infrastructure, and the safety of first responders. Commercial trace detectors can measure signals from nanogram-sized analytes in complex matrices, but even with preventative maintenance, detector performance can degrade over time. A sensitive indicator of performance is the limit of detection (LOD), which is distinctive for each target compound in each model of detector for a given set of operating parameters. ASTM subcommittee E54.01, with help from industry and agency stakeholders, recently promulgated E2677 Standard Test Method for Determining Limits of Detection in Explosive Trace Detectors. The Method allows a well-characterized LOD to be determined in accordance with ISO measurement and uncertainty concepts, and IUPAC detection concepts. Challenges of background interference, response non-linearity, heteroscedastic behavior, and truncation by signal filters were considered. Data are input to a Webtool on a NIST cloud server where data quality is assessed, LOD calculations are performed, and results returned to the user. The Method is gaining use worldwide as a well-documented mechanism for monitoring and intercomparing LOD values and is now being considered in ASTM for a wider audience of users. Here, we describe some of the details of the Method and offer two other examples: 1) ozone measurements that were simultaneously collected on two commercial monitors and the NIST Standard Reference Photometer; and 2) trace opioid samples that were measured using a variety of techniques: ion mobility spectrometry, GC/MS, and mini-DART-MS. Many environmental applications could benefit from such an approach, so we seek case studies for assessment.