Composition of Explosives by Electrospray Ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

Abstract

Commercial explosives are complex mixtures that contain not only the active explosive agent(s) but also a host of other organic and inorganic compounds. The ultrahigh mass resolving power (m/delta m50% >200,000) and mass accuracy (<1 ppm) of electrospray ionization Fourier transform ion cyclotron resonance (ESI FTICR) mass spectrometry allow for definitive identification of various species in TNT, RDX, and HMX. We are thereby able to correct prior misassignments of the elemental compositions of the most abundant negative ions from electrospray of RDX and HMX. Although the (known) active agents of many explosives may be identified by low-resolution MS or MS/MS, it is the other characteristic components (indigenous or artificial additives) whose presence and elemental composition can potentially identify the source of the product. ESI FTICR mass spectrometry of smokeless powder, TNT, and Powermite resolves and identifies numerous nonactive ingredients, many of which are recovered in a postblast residue. In contrast, the residue recovered from an explosion of military C4 yielded several species derived from RDX but virtually none from other ingredients.

Mass Spectrometric Analysis of Eight Common Chemical Explosives Using Ion Trap Mass Spectrometer

“…10 The presence of formate could also be due to a trace amount of formic acid left from previous experiments. Even though the system was thoroughly cleaned with acetonitrile, methanol, and water for the current investigation, it is possible that a trace level of formic acid still exists in the system as an impurity.…”

“…7,10 To improve the signals of the [M+Cl] -ions, chloride ions were often intentionally added. 7 Recently, the addition of HCl to the spray solvent in the DESI analysis of RDX and HMX provided [M+ 35 Cl]…”

Experimental evidence for space-charge effects between ions of the same mass-to-charge in Fourier-transform ion cyclotron resonance mass spectrometry

“…The ultrahigh mass accuracy provided by FT-ICR makes it possible to determine the elemental composition of small and large molecules from direct mass measurement [6][7][8][9]. Since the introduction of electrospray ionization (ESI) and matrixassisted laser desorption/ionization (MADLI), the demand for higher mass accuracy has increased with the growing complexity of the samples and of the average mass of the samples.…”

Optimized Automatic Noise Level Calculations for Broadband FT-ICR Mass Spectra of Petroleum Give More Reliable and Faster Peak Picking Results

“…The ultra-high mass resolution of FT-ICR MS often makes it possible to identify organic molecules based solely on the measured mass to charge (m/z) values. FT-ICR MS has been successfully applied to organic mixtures such as metabolites, 1 vegetable oils, 2 wine, 3 explosives, 4 coal extracts, 5 humic materials, 6,7 and crude oils. 8,9 Broadband FT-ICR MS spectra of these types of organic mixtures are usually very complex, with peaks appearing over a wide dynamic range.…”