APPLYING THE SCIENCE 10.3 Immersed Explosives

The crash of TWA Flight 800 (Chapter 9, Exhibit B) raised the critical issue of how immeision in water affects analyses of explosives. The results of recent experiments show that the persistence of explosives residues depends on 

Source Kamyshny, A., et al. Water-Soaked Evidence Detectability of Explosive Traces after Immersion in Water. Journal 

Given the variety of explosives, it is no surprise that chromatography is central to their analysis. Techniques that are or have been used include TLC, GC, HPLC, ion chromatography, CE, MEKC, supercritical fluid extraction, and size exclusion chromatography. Samples can be prepared for chromatographic analysis with simple solvents using water, acetone, and the like. SPME is also used to preconcentrate samples, particularly when the explosives must be extracted from an aqueous environment. SPME can be adapted to HPLC to avoid thermal degradation issues that commonly arise in explosives. Another approach is to derivatize the explosives directly on the fiber such that the derived substance can be analyzed by means of GC.  

Ion chromatography is a valuable tool for explosives analysis, although the associated instruments are not found in most forensic laboratories. Target 

This concludes the combustion portion of the text. Next we move into the world of colorants—pigments and dyes. These compounds, are the key ingredients in paints, inks, and dyes, and will lead us into an exploration of questioned documents and the world of trace evidence such as fibers. 

---