| Popis: |
The continuing threat of worldwide terrorism has prompted the need for new and innovative explosives detection systems. As part of an ongoing research effort, the FBI Laboratory has been evaluating new technology and the innovative adaptation of existing technology for use in counterterrorism and counternarcotics investigations. We have been examining the application of ion mobility spectrometry (IMS), for its role in explosives detection. The explosives residue is collected on a membrane filter by a special attachment on a household vacuum. Subsequent thermal desorption and analysis requires 5 seconds. Experimental results have determined the limits of detection for most common explosives to be approximately 200 pg. The persistence of explosives on hands and transfer to other surfaces has been examined. Post-blast residue of NG was detected on fragments of improvised explosive devices constructed with double-based smokeless powder. Post-blast residue from C-4, SEMTEX, and other explosives have also been detected on items of forensic and evidentiary value. |
