title: Automated mapping of explosives particles in composition C-4 fingerprints.
abstract: A method is described to perform automated mapping of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) particles in C-4 fingerprints. The method employs polarized light microscopy and image analysis to map the entire fingerprint and the distribution of RDX particles. This method can be used to evaluate a large number of fingerprints to aid in the development of threat libraries that can be used to determine performance requirements of explosive trace detectors. A series of 50 C-4 fingerprints were characterized, and results show that the number of particles varies significantly from print to print, and within a print. The particle size distributions can be used to estimate the mass of RDX in the fingerprint. These estimates were found to be within +/-26% relative of the results obtained from dissolution gas chromatography/micro-electron capture detection for four of six prints, which is quite encouraging for a particle counting approach. By evaluating the average mass and frequency of particles with respect to size for this series of fingerprints, we conclude that particles 10-20 microm in diameter could be targeted to improve detection of traces of C-4 explosives.
authors.affiliation: National Institute of Standards and Technology, Gaithersburg, MD, USA.
authors.forename: Jennifer R
authors.initials: JR
authors.lastname: Verkouteren
authors.forename: Jessica L
authors.initials: JL
authors.lastname: Coleman
authors.forename: Inho
authors.initials: I
authors.lastname: Cho