Title

Novel Applications Of Lc/Ms In Forensic Analysis Of Explosives

Abstract

Identification and characterization of explosives is of major significance in both forensic analysis of post-explosion residues and in environmental analysis of explosives-contaminated areas. In addition to the type of explosive, it is important to know the country of origin of the explosive and preferentially its manufacturer. Each manufacturer will produce the explosive with characteristic differences in the type and amount of impurities, by-products and additives, depending on the purity of raw materials and solvents used and the type of manufacturing process, resulting in a typical profile of by-products, organic impurities and additives. In TNT, a typical group of by-products are the isomers of TNT, DNT, TNB and DNB, whose profile depends on the manufacturing process and the amount of purification of the raw product. As the amount of these by products is very small, a highly sensitive and selective analytical method is needed for their identification. Liquid chromatography/mass spectrometry (LC/MS), with atmospheric pressure chemical ionization (APCI), in the negative-ion mode, was found to provide best sensitivity and selectivity requirements. Preliminary results showed that TNT samples from different countries of origin, analyzed by LC/MS, had different profiles of TNT, DNT, TNB and DNB isomers. Inorganic salts have been used extensively as oxidizing agents in various explosive mixtures. In order to develop an analytical method for identification of these oxidizers in post-explosion residues, we have studied the electrospray ionization mass spectrometry (ESI-MS) of a group of 11 inorganic oxidizers. ESI-MS is a soft ionization technique where ions in the liquid phase in the sample solution are transformed to gas-phase ions by a process of generating highly charged droplets followed by "ion evaporation". Results showed that in the positive-ion mode, cluster ions, containing intact molecules, are formed when the heated capillary is at temperatures in the range of 50-100°C. These cluster ions can be used for identification of the oxidizer.

Publication Date

6-1-2002

Publication Title

Explosion

Volume

12

Issue

2

Number of Pages

69-76

Document Type

Article

Personal Identifier

scopus

Socpus ID

0036619816 (Scopus)

Source API URL

https://api.elsevier.com/content/abstract/scopus_id/0036619816

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