The Application of Analytical Methods to the Detection of Hidden Explosives and Explosive Devices

Abstract

The detection of hidden explosives has undergone an enormous development due to an increased desire for safety and the increased terrorist attacks in the last few years. This development was made possible in particular by the rapid advances in the development of powerful analytical techniques in general. These technologies. however, must be specially adapted for the problems of explosives detection. These problems encompass. for example. the large variety of different explosives, the camouflage of explosive devices, and the complexity of the composition of suspicious objects. Frequent an-travelers have most certainly ~~~ already been confronted with a so-called explosives detection apparatus. Baggage controls at airports are a very important and well-known example of the application of detection technologies. This example also serves to demonstrate the high technological requirements, such as the variability of the object to be examined and a control procedure for a sealed object that must be completed with high reliability in a short period of time. The search for explosive devices or weapons cannot, however, be limited to the recognition of an external appearance with the help of X-ray imaging. These days, explosive devices, in particular, can readily be installed and hidden in objects of daily life by the use of tiny electric and electronic elements. Therefore, in addition to the application of X-ray imaging, the use of other technologies becomes necessary. The following article describes and discusses methods and scientific limits of explosives detection under the precondition of possible use at security checkpoints.

A positively charged silver nanowire membrane for rapid on-site swabbing extraction and detection of trace inorganic explosives using a portable Raman spectrometer

“…requires analytical methods with high speed and sensitivity [2,3]. Numerous analytical methods, such as laser photoacoustic spectroscopy [4], fluorescence [5][6][7], surface-enhanced Raman spectroscopy (SERS) [8,9], nano-electrical devices [10], mass spectrometry, ion mobility spectroscopy, and X-ray imaging [11] have been used or proposed as suitable methods for the detection and quantification of nitro-explosives, such as 2,4,6-trinitrotoluene (TNT), 2,4-dinitrotoluene (DNT), cyclo-1,3,5-trimethylene-2,4,6-trinitramine (RDX) and 2,4,6-trinitrophenol (TNP) et al Capillary electrophoresis (CE) [12], ion chromatography (IC) [13], electrospray ionization mass spectrometry (ESI-MS) [14], and electrospray ionization ion mobility spectrometry (ESI-IMS) [15] have been employed to detect characteristic ions of inorganic explosives, such as ClO 4 − , ClO 3 − , or NO 3 − [16,17], which are known for their high stability and non-volatility. Recently, the capability of thermal desorption ion mobility spectrometry (TD-IMS) for the on-site sensitive detection of typical nitro-explosives such as TNT and RDX has been demonstrated.…”

Spectroscopic characterization of explosives in the far-infrared region

“…[2][3][4][5] Research in this field has significantly grown since the attacks on the World Trade Center on September 11, 2001. Explosives have been characterized by a number of spectroscopic techniques, such as middle-FTIR, Raman, UV/visible spectroscopy, GC-MS, etc.…”

A water-soluble cationic oligopyrene derivative: Spectroscopic studies and sensing applications

“…However, all these techniques are complicated, expensive, and limited by either lack of sensitivity or ability of rapid detecting trace of TNT. Fluorescence quenching is also a useful and effective method for detecting explosive nitroaromatic compounds [2][3][4][5][6]. Various materials have been employed in fabricating fluorescent sensors such as conjugated polymers [7][8][9][10][11][12], small fluorescent molecules [13,14], dye-doped silica [15,16], and nano-scaled molecular aggregates [17].…”