NCJ Number
140912
Journal
Journal of Forensic Sciences Volume: 38 Issue: 1 Dated: (January 1993) Pages: 28-39
Date Published
1993
Length
12 pages
Annotation
The Federal Bureau of Investigation (FBI) has been evaluating various technologies for use in counterterrorism and counternarcotics investigations, and ion mobility spectrometry (IMS) may be a useful technique for explosives detection.
Abstract
In the IMS technique, explosives residue is collected on a membrane filter by a special attachment on a household vacuum. Subsequent thermal desorption and analysis require 5 seconds. Experimental results indicate the limits of detection for most common explosives to be about 200 pg. The vacuum sampling method permitted the collection of trace physical evidence transferred to hands or surfaces through contact or postblast residue. Laboratory measurements of the sensitivity and specificity of IMS showed detection as low as 200 pg for common explosives. The demonstrated retention of explosives on hands and the contact transfer to other surfaces offer law enforcement investigators potential new sources for collecting trace physical evidence associated with suspected terrorism. The detection of postblast residue from improvised explosive devices can aid the investigator at a bomb scene by providing a rapid means of screening evidence for further laboratory evaluation. 15 references, 4 tables, and 7 figures