Applications of Vibrational Spectroscopy in the Study of Explosives

Abstract

The sections in this article are Introduction Background on Explosives Materials Handling Vibrational Spectroscopy Applications Methods – Non‐Thermal Techniques Transmission FT ‐ IR Spectroscopy Attenuated Total Reflection ( ATR ) Infrared Microscopy FT ‐ IR Photoacoustic Spectroscopy Diffuse Reflection FT ‐ IR Spectroscopy Surface‐Enhanced Infrared and Surface‐Enhanced R aman Spectroscopy Grazing Angle Reflection/Absorption FT ‐ IR Spectroscopy Theoretical Calculations R aman Spectroscopy Methods – Thermal Techniques Rapid‐Scan FT ‐ IR Spectroscopy DAC / GAC – Microspectroscopy Transmission FT ‐ IR Spectroscopy of Thin Films High Temperature FT ‐ IR Spectroscopy Low Temperature FT ‐ IR Emission FT ‐ IR Spectroscopy R aman Spectroscopy Conclusion Acknowledgments

Post-blast detection of traces of explosives by means of Fourier transform infrared spectroscopy

“…The aim of this study was also to demonstrate, for the first time, that synchrotron-radiation-based FTIR spectroscopy is a particularly selective and sensitive method for the analysis of traces of explosives in post-blast residues. FTIR spectroscopy is certainly one of the most important analytical techniques available to date [15,16] and has been successfully used to analyze pure explosive materials in many laboratories worldwide [17,18]. However, to our knowledge, this method has not been applied to the analysis of post-blast residues [14].…”

Hyperspectral imaging for non-contact analysis of forensic traces

“…The improved speed of HSI compared to spectroscopy, is particularly of advantage in hazardous environments. In explosives investigations especially, the ability to measure specimens without contact or specimen preparation is beneficial, as many accidents occur even when trained personnel handle explosives [72].…”

Laser-Based Detection Methods for Explosives

“…The infrared absorption spectra of many neat solid explosives appear as fairly broad features resulting from the blending together of rovibrational lines corresponding to a given vibrational transition. The broad spectral features of many solid explosives (including their vapors) in the infrared lend themselves to measurement by broad band techniques such as Fourier-transform (FT) infrared spectroscopy (10). Laser-based methods of detection by infrared absorption techniques are often limited by the bandwidth of the light source (this is not necessarily the case with Raman spectra of many neat solid explosives; for this reason, Raman spectroscopy has been used extensively for analysis of solid explosives (11) (see section 2.2).…”

“…Applications to explosives sensing using semiconductor light sources have been reviewed by Allen et al (14). Traditional detection methods (Beer-Lambert law-type experiments) are somewhat limited because the broad spectral features of many neat explosive vapors make phase sensitive detection methods difficult (10,12). Because of this, TDLAS is often used to detect and measure light gases (e.g., NO and NO 2 ) produced by decomposition of the parent explosive.…”