Reducing False Alarms in Ion Mobility Spectrometry Detectors: Determination of Accurate and Precise Reduced Mobility Values
Abstract
Ion mobility spectrometry (IMS) is a widely used analytical technique for field detection of chemical warfare agents (CWAs), narcotics, and explosives. Detection is based on the reduced mobility (K0) of the compound of interest (COI). The detection windows for COIs have historically been as small as +/- 2% of the predicted COI K0 value (K0 COI), which resulted in false-positive alarms when an interferent appeared within these wide detection windows. Accurate K0 values that are an order of magnitude better than the values given in literature lower the propagation of error when they are used to predict the drift time of an ion and reduce the width of the detection windows. An IMS instrument was constructed and interfaced with an existing time-of-flight mass spectrometer, and select K0 COI values were measured as a function of multiple instrumental parameters. This initial database of accurate K0 COI values will be expanded in the future to include additional COIs, namely CWAs (toxic chemicals) and explosives. The database of accurate K0 values will be used to calibrate IMS-based field instruments and reduce their rates of false-positive alarms without increasing their false-negative responses or modifying hardware.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 2017
- Accession Number
- AD1041931
Entities
People
- Brian C Hauck
- Charles S. Harden
- Herbert Jr H. Hill
- Vincent M. Mchugh
- William F. Siems
Organizations
- Edgewood Chemical Biological Center