Explosive threats

Among other things, one prerequisite necessaiy to calculate the pressure relief openings needed on the apparatus is knowledge about the explosion threat definition and venting system hardware definition. Tne various influences are summarized in Table 26-22. 

Flammability and detonability limits. The broader flammability and detonability limits of hydrogen coupled with its rapid burning velocity renders hydrogen a greater explosive threat than methane or gasoline. 

The guiding principle for responding to severe release or explosion threats is one of due diligence—or What is a suitable and sensible response to a threat As discussed above, some response to chemical contamination threats is warranted due to the public health implications of an actual contamination incident. However, a chemical facility could spend a lot of time and money overresponding to every threat, which would be an ineffective use of resources. Furthermore, overresponse to threats carries its own adverse impacts. 

Erythritol tetranitrate (ETN) (Figure 1) is an explosive first prepared in 1849 [1] with similar properties to pentaerythritol tetranitrate (PETN). ETN is melt-castable, has impressive performance, and is not difficult to prepare, which increases the necessity for understanding its properties from a homemade explosive threat determination perspective [2]. Due to its handling sensitivity, ETN has been involved in recent accidents [3] and should not be handled outside of a dedicated explosives facility. We have recently reported the first X-ray crystal structure of ETN [4], and discussed the influence of crystal packing on the sensitivity of the material, relative to PETN [5]. Another recent publication also discusses basic characterization of ETN [6]. 

The use of MS in the detection of CBRNE threats to HLS has been gaining momentum in the last decade. MS weighs atoms and molecules according to their mass-to-charge ratios and is used to identify, characterize, and quantify compounds used in chemical, biological, radiological, or explosive threat devices [7-10]. MS, coupled to either a gas or hquid sample separation technique, is used extensively for the detection of chemical... 

Various Ionization Methods for Trace Explosive Threat Detection by IMS Several articles and books review IMS for trace explosives detection [18, 45, 48]. In particular, a review article, describes many of the product ion formation reactions that create IMS product ions from explosive compounds [45]. The review also contains extensive tables of reduced mobility (Ko) values, which are used to identify ions in IMS, for the most common explosive compounds. 

Differential Mobility-MS for Explosive Threat Detection Differential mobility spectrometry (DMS), also known as FAIMS, is a technique closely related to IMS [191-192]. In this system, the ratio of the electric field strength (E, V/cm) applied to the electrodes to the drift gas number density (N, cm" ) is increased to a level beyond that used in DT-IMS (the most common configuration of IMS systems) so that the mobility of the ion (K) is no longer constant but is dependent on the strength of E/N (Townsend [Td]) [192]. 

Various ionization sources are employed in the analysis of explosives by MS. APCI is used with GC-MS, LC-MS, and LC-MS/MS systems for explosives analysis [200-204] this source is chosen because lower LOD can be found with APCI over El sources. However, El remains the ionization source used most often in GC-MS analyses of explosives [12,134-137,139-143,205], DESI, desorption atmospheric pressure chemical ionization (DAPCI), and direct analysis in real time (DART) sources are used to detect explosives, including emerging explosive threats like TATP and as part of field-deployable MS systems [163,206-209],... 

Miniaturized Mass Analyzers for Explosive Threat Detection... 

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