The Recovery and Identification of Ethyleneglycoldinitrate and Nitroglycerine in Explosion Debris Using Preconcentration and High Performance Liquid Chromatography

Chemical Classification of Explosives

This work comprehensively reviews some fundamental concepts about explosives and their two commonly used classifications based on either their velocity of detonation or their application. These classifications are highly useful in the military/legal field, but completely useless for the chemical determination of explosives. Because of this reason, a classification of explosives based on their chemical composition is comprehensively revised, discussed and updated. This classification seeks to merge those dispersed chemical classifications of explosives found in literature into a unique general classification, which might be useful for every researcher dealing with the analytical chemical identification of explosives. In the knowledge of the chemical composition of explosives, the most adequate analytical techniques to determine them are finally discussed.

On-line coupling of supercritical fluid extraction with high-performance liquid chromatography for the determination of explosives in vapour phases

An analytical method for determining nitroaromatic explosives in vapour phases is presented. Samples were collected by pumping air through glass fibre filters and polyurethane foam adsorbents, and an on-line extraction system combining supercritical fluid extraction (SFE) and high-performance liquid chromatography (HPLC) was developed. This allows analytes to be transferred from the adsorbent to the HPLC system via a porous graphitic carbon trap. When using gradient elution with a suitable mobile phase, most of the nitroaromatic isomers tested were separated. The proposed method is fully automated, allows a complete analysis to be processed in less than 30 min, and it is compatible with most of the organic solvents commonly used as SFE modifiers or additives. The method has been applied to the analysis of real samples obtained from headspace sampling of military-grade 2,4,6-trinitrotoluene and has been shown to constitute a promising alternative for assessing whether areas are mined in landmine-clearing operations.

Performance evaluation of an in-injection port thermal desorption/gas chromatographic/negative ion chemical ionization mass spectrometric method for trace explosive vapor analysis

A gas chromatographic method utilizing thermal desorption of Tenax TA and sol-gel sorbent traps has been developed and validated for the analysis of trace explosive vapor with negative ion chemical ionization mass spectrometric detection. Sorbent tubes were packed with Tenax TA and sorbent particles prepared in-house by the sol-gel process. Thermal desorption was performed within a split/splitless injection port with minimal instrument modification. Performance was characterized by relative thermal desorption recovery, precision (reproducibility), linearity of the calibration, and method detection limits. Method validation was performed with a series of dinitrotoluenes, dinitrobenzene, trinitrotoluene, trinitrobenzene, two aminodinitrotoluenes, three nitroesters, and two nitramines. The performance of Tenax TA and the sol-gel sorbents is evaluated based on the method validation data. The method was applied to the analysis of trace explosive vapor collected and concentrated with sol-gel solid sorbent traps from the headspace of a smokeless gunpowder sample.