Vapor Pressure of Linear Nitrate Esters Determined by Transpiration Method in Combination with VO‐GC/MS

Abstract

Gas phase detection of explosives is an ongoing trend in the detection sciences. The conception of gas phase detection devices requires knowledge about gas phase concentration of the target analytes. Nitrate esters are well performing explosives with a high potential for misuse in improvised explosive devices that need to be detected at vulnerable infrastructures. With respect to this the six nitrate esters, ethyl nitrate (1), ethylene glycol dinitrate (2), glycerol trinitrate (3), meso‐erythritol tetranitrate (4), d‐mannitol hexanitrate (5) and pentaerythritol tetranitrate (6) were investigated in terms of detectability by vacuum outlet‐GC/MS as potential components in improvised explosive devices. All compounds besides 5 could be detected using vacuum outlet GC/MS and their limits of detection were determined according to DIN 32645 : 2008. The vapor pressure of 2–4 was measured using the transpiration method. It was observed that the introduction of a CHONO2 unit lowers the vapor pressure of the nitrate esters by about two orders of magnitude. For compound 4 the saturation concentration (73 ng L−1) was compared with a vapor pressure based estimation of its concentration in diffusion equilibrium (0.385 pg L−1).

Modifying Nitrate Ester Sensitivity Properties Using Explosive Isomers

“…Because of the difference in explosive sensitivity of ETN and its diastereomers, we chose to look at another pair of explosive diastereomers, MHN and SHN (Scheme ). Both MHN and SHN have been reported in the literature and are both solids at room temperature. , These complexes were synthesized following literature reports and obtained as white solids. MHN was isolated as a stable white powder with no decomposition observed over weeks.…”

“…NMR signals were referenced using residual solvent signals. Mannitol hexanitrate and sorbitol hexanitrate were prepared according to literature procedures. , Samples were prepared on a 2 g scale.…”

“…Nitrate esters are a common class of explosive molecules that are well-known for their straightforward synthesis procedures from the corresponding sugar molecules. Common nitrate ester explosives include pentaerythritol tetranitrate (PETN), erythritol tetranitrate (ETN), and mannitol hexanitrate (MHN), which have recently received attention in the literature due to their potential use as homemade explosives. − For example, recent reports have studied possible factors that can affect ETN stability, including particle size and physical state . However, diastereomers of ETN have not been synthesized or investigated.…”

Phlegmatization of TATP and HMTD with Activated Charcoal as Training Aid for Explosive Detection Dogs

“…The quantification of the analytes was carried out with vacuum-outlet gas chromatography coupled with mass spectrometer (VO-GC/ MS) [40] using a Shimadzu QP2010 SE device. Along with the obtained experimental p-T data, corresponding thermodynamic parameters and fit-functions in a form of a modified Clarke-Glew equation [41] were derived. Table 2 provides the isobaric molar heat capacities and their differences for TATP, which are necessary for the adjustment of the molar enthalpies of sublimation to the reference temperature (298.15 K) according to the procedure discussed in the work of Chickos et al [42].…”

Characterization of the Hexanitrate Esters of Sugar Alcohols

“…MHN was prepared via mixed acid nitration according to published literature procedures [23, 24]. Fuming nitric acid was chilled in an ice bath and mannitol was slowly added, maintaining a temperature less than 10 °C.…”