Nitrate ester explosives

Walsh ME. Determination of nitroaromatic, nitramine, and nitrate ester explosives in soil by gas chromatography and electron capture detector. Talanta 2001 54 427-438. 

Otto Fuel II, a liquid propellant used exclusively by the U.S. Navy in torpedoes and other weapon systems, is a mixture of three synthetic compounds 1,2-propylene glycol dinitrate (PGDN) (a nitrate ester explosive), dibutyl sebacate (a desensitizer), and 2-nitrodiphenylamine (a stabilizer). The... 

The following examples illustrate the range of apphcations of LC/MS for trace analysis of explosives ESI-LC/MS/MS-CID fragmentation processes of a series of nitroaromatic, nitramine and nitrate ester explosives were studied in the negative-ion mode using daughter-ion, parent-ion and neutral loss scans [14]. Table 1 shows the CID daughter ions in ESI-MS/MS of TNT. 

Several additives were tested with a series of explosives in order to enhance ESI intensities [15—17]. Nitramine and nitrate ester explosives showed enhanced response for ammonium nitrate additive, by forming [M + NOs] adduct ions in the negative-ion mode. Nitrate adduct ions were more intense than trifluoroacetate (TFA) or chloride adduct ions by a factor of 6-40. The base peak in the negative-ion mass spectrum of TNT, with 1 mM ammonium nitrate in the mobile phase was at m/z 226 due to the [M-H] ion. 

X. Xu, A.M. van der Craats and P.C.A.M. de Bmyn, Highly sensitive screening method for nitroaromatic, nitramines and nitrate ester explosives by high performance liquid chromatography — atmospheric pressure ionization — mass spectrometry (HPLC-APl-MS) in forensic applications , J. Forensic Sci., 49 No. 6 (2004) 1171-1180. 

Henry reactions have been extensively exploited for the synthesis of nitrate ester explosives. The condensation of nitroalkanes with aldehydes, followed by esterification of the hydroxy groups with nitric acid, leads to a number of nitrate ester explosives (see Chapter 3). The two examples given above (166 and 167) are synthesized from the C-nitration of the polyols obtained from the condensation of formaldehyde with nitromethane and nitroethane respectively. 

A huge number of ester and carbonate derivatives of polynitroaliphatic alcohol have been synthesized driven by the search for new explosives and energetic plasticizers and oxidizers for propellant and explosive formulations. Most of these are derived from 2-fluoro-2,2-dinitroethanol and 2,2,2-trinitroethanol ° and have excellent oxygen balances. Some examples are illustrated above (168-174) but more comprehensive lists can be found in numerous reviews. " " Direct esterification of polynitroaliphatic alcohols with nitric acid, mixed acid, or acetic anhydride-nitric acid has been used as a route to mixed polynitroaliphatic-nitrate ester explosives. ... 

Pentaerythritol tetranitrate (PETN) (3) is a powerful explosive which exhibits considerable brisance on detonation (VOD 8310 m/s at = 1.77 g/cm ). It is the most stable and least reactive of the common nitrate ester explosives. The relatively high sensitivity of PETN to friction and impact means that it is usually desensitized with phlegmatizers like wax and the product is used in detonation cord, boosters and as a base charge in detonators. Pentaerythritol tetranitrate can be mixed with synthetic polymers to form plastic bonded explosives (PBXs) like detasheet and Semtex-IA. A cast mixture of PETN and TNT in equal proportions is known as pentolite and has seen wide use as a military explosive and in booster charges. The physical, chemical and explosive properties of PETN commend its use as a high explosive. 

An interesting example of the effectiveness of different reagents for 0-nitration can be seen during the synthesis of neo-inositol-based nitrate ester explosives. l,4-Dideoxy-l,4-dinitro-neo-inositol (15), a compound readily prepared from the condensation of nitromethane and glyoxal in the presence of base,undergoes conversion to the tetranitrate ester (16) on... 

The dihydroxylation of alkenes is a useful sttategy for the synthesis of polyols and these can be nitrated to the corresponding nitrate esters. Evans and Gallaghan " synthesized both the mono- (74) and di- (70) allyl ethers of pentaerythritol and used these for the synthesis of some novel nitrate ester explosives. 

The energetic nature of the N-NO2 group means that At-nitro-based explosives are some of the most powerful explosives available and these have largely superseded aromatic C-nitro compounds for military applications. Many nitramines exhibit high brisance and high chemical stability in combination with a favourable low sensitivity to impact and friction compared to nitrate ester explosives of similar power. 

Bratin, K., P. T. Kissinger, R. Briner, and C. Bruntlett. Determination of nitro aromatic, nitramine, and nitrate ester explosive compounds in explosives mixtures and... 

Erythritol tetranitrate is a melt-castable, high-performance nitrate ester explosive that has recently become important due to its use in homemade explosives. We have investigated the detonation behavior of ETN using cylinder tests and small diameter unconfined rate sticks. Similar performance properties were observed between ETN and the closely related nitrate ester, PETN detonation velocities for the two... 

Examination of the structures of nitrate ester explosives shows that they contain abundant carbon derived from polyhydric alcohols (e.g. glycerol, pentaerythritol) which are readily assimilable by bacteria. Moreover nitrate esters also contain abundant nitrogen and thus they may also serve to supply this element for microbial growth. A... 

GC-MS is used to detect both common and emerging explosive compounds. A review of GC-MS methods used to detect organic explosive compounds is available [129]. T vo common GC-MS sample introduction techniques are solid-phase microextraction (SPME) and headspace vapor collection [130-133], TTiese sample introduction methods are employed in the analysis of water and soil samples with suspected explosive residue contamination [134-137]. The U.S. EPA Method 8095, Explosives by Gas Chromatography, is recommended as a resource for sample preparation of soil and water samples analyzed for the common nitroaromatic, nitra-mine, and nitrate ester explosive compounds [138]. 

LC-MS is another widely used analytical method for the analysis of explosives. Several articles review LC-MS for explosives analysis [150-152], In particular, Wnon and his coworkers have significantly contributed to the development of explosives analysis by LC-MS. Zhao and Yinon identified nitrate ester explosives by LC-MS using both ESI and APCI [153], In both ionization studies, postcoluran additives are introduced to increase specificity and sensitivity of the product ions produced by the explosives pentaerythritol tetranitrate (PETN), nitroglycerin (NG), and ethylene glycol dinitrate (EGDN) to form stable adduct ions (as shown in Figure... 

FIGURE 20.15 Extracted ion chromatograms from the LC-ESI-MS analysis of three explosives in a mixture with addition of ammonium nitrate after the LC separation 2 ng/mL EGDN, 10 pg/mL NG, and 10 pg/mL PETN. Source Zhao, X., Yinon J. (2002) Identification of nitrate ester explosives by liquid chromatography-electrospray ionization and atmospheric pressure chemical ionization mass spectrometry. Journal of Chromatography A, 977, 59-68. 

Zuo,Y.,et al.(2008) Interaction of nitrate ester explosive and polyurethane binder. Huaxue Yanjiu Yu Yingyong, 20, 691-695. 

Zhao, X., Yinon, J. (2002) Identification of nitrate ester explosives by liquid chromatography-electrospray ionization and atmospheric pressure chemical ionization mass spectrometry. Journal of Chromatography A, 977, 59-68. 

TABLE 14. The drop-weight impact sensitivities of nitrate ester explosives,... 

Gas chromatography-mass spectrometry was used for the quantitative analysis of a series of nitrate ester explosives 1,2,4-butanetriol trinitrate (BTTN), triethylene glycol dinitrate (TEGN), metriol trinitrate (MTN, 1,1,1-tri(hydroxymethyl) ethane trinitrate), PGDN, NG and PETN [19]. The MS ionization techniques included El, Cl and NCI. Methane was the usual reagent gas for Cl and NCI, but isobutane and ammonia were also studied. Quantitation was carried out using SIM. 

Some unusual adduct ions, corresponding to [M + NO] and [M + N02], appear in the mass spectra of nitrate ester explosives, such as NG and PETN, and nitramines, such as RDX and HMX [38, and references cited therein]. Their formation, which is favored by GI MS conditions, especially in high sample pressures, is attributed to ion-molecule reactions between NO and N02 ions and the neutral molecules of the explosives. These adduct ions were also reported to be highly abundant in the El spectra of nitrate esters [19], when El was carried out in a tight, dual EI/CI ion source. 

White, G.F., Snape, J.R., Nicklin, S., 1996. Bacterial biodegradation of Nitrate Ester Explosives. In Kaffka, A.V. (Ed.), Sea-Dumped Chemical Weapons Aspects, Problems and Solutions. Kluwer Academic Publishers, Dordrecht, pp. 145-156. 

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