Trinitrotoluene determination

Trinitrotoluene, TNT, is a well-known explosive, (a) Using the structure available on the Web site, determine the systematic name for TNT. (b) TNT is made by nitrating toluene (methylbenzene) with a... 

W. Taylor and Cope [55] determined the minimum charge of a mixture of mercury fulminate (90%) and potassium chlorate (10%) necessary to detonate mixtures of trinitrotoluene and tetryl (Table 12). 

TNT was first prepared in 1863 by Wilbrand and its isomers discovered in 1870 by Beilstein and Kuhlberg. Pure TNT (2,4,6-trinitrotoluene isomer) was prepared by Hepp in 1880 and its structure determined by Claus and Becker in 1883. The development of TNT throughout the 19th and 20th centuries is summarized in Table 2.11. 

It has been established experimentally (T. Urbanski, Kwiatkowski, Miladowski [22]) that the addition to pentaerythritol tetranitrate of such nitro compounds as nitrobenzene, nitrotoluene, dinitrobenzene, dinitrotoluene, trinitrobenzene, and trinitrotoluene, decreases its stability as determined by heating to 120-135°C. The degree of decomposition of PETN, heated alone or in mixtures, can be estimated in terms of the pH-values determining the acidity of the decomposition products (Table 32, Fig. 72). 

Schiff, A Colorimetric Method for the Determination of 2,4,5-Trinitrotoluene , Edgewood-AisTechRept EC-TR-73068 (1974) 12) M.C. 

F. Pristera, Infrared Method for Determination of Alpha, Beta, Gamma-Trinitrotoluene in Exudate Admixtures , ApplSpectroscopy 7,115— 21 (1953) 19) H. Herman, Determination of... 

VM. Aksenenko Z.V. Tatamikova, Potentiometric Determination of Trinitrotoluene in Non-Aqueous Media in Presence of Nitric and Sulfuric Acids , ProblAnalKhim 1,118—24... 

J. Flack, Polarographie Determination of Trinitrotoluene in the Presence of Dinitro-toluene , HungScilnstrum 32, 11-12 (1975)... 

Analytical Method for Determining Trinitrotoluene in Water , USP Applic 770718 (1978) 161) omit 162) R J. Kopec et al, Forensic... 

Nitrogen-containing explosives [249] and trinitrotoluene [250] have been determined in soil by gas chromatography with thermionic NP detection and reverse-phase high-performance liquid chromatography. Warmont et al. [251] used tunable infrared laser detection to study the pyrolysis products of explosives in soil. 

Trinitrotoluene and RDX have been determined in soil using a field-portable continuous-flow immunosensor. Results agreed with those obtained by high-performance liquid chromatography [255,256]. 

More complex chemical species have been determined using different cappings on the QDs surfaces. Shi et al. have recently demonstrated that QDs coated with oleic acid were efficiently quenched by a diversity of nitroaromatic explosives, such as 2,4,6-trinitrotoluene (TNT) or nitrobenzene.49 Different quenching behaviors were observed for the different molecules. Nevertheless, modified Stern-Volmer equations could be used, in most cases, to provide linear calibration curves. Time domain measurements showed that static quenching was the dominant process as no change in luminescence lifetime was observed in the presence of the analyte. 

The woik of Bennett and his co-workers [87] (discussed in detail on the p. 312) was an exception a 50/50 mixture of di- and tri-nitrotoluene was nitrated by shaking with mixed acids of various compositions for a fixed time. The reaction was then quenched with cold water and the proportion of the dinitrotoluene which has been converted to trinitrotoluene was determined. The conversion, Mid the reaction rate, approach zero as the mole ratio water sulphuric acid approaches unity. This is significant, because if this ratio considerably exceeds 1.0 the N02+ ion is spectroscopically undetectable in sulphuric acid-nitric acid-water solutions. Bennett showed that various acid mixtures that gave the same conversion contained practically the same concentration of the N02+ ion, as determined by Raman spectra. Hetherington and Masson [84] had already found that the reaction rate became negligibly small at certain concentrations and that a line drawn through the limiting boundary almost coincides with the boundary of the area of spectroscopic detection of N02+ ions. 

Melting point and purity. The melting point of a- trinitrotoluene has been determined by several workers as 80.6°C, 80.65°C, 80.8-80.85°C, 80.66°C. The value of 80.65°C is generally accepted, and usually determined as setting point. 

Since the trinitrotoluene isomers are formed as a result of the nitration of m- ni-trotoluene, W. W. Jones and Russel [9] undertook the task of determining to what extent the presence of m- nitrotoluene in mononitrotoluene lowers the melting point of a- nitrotoluene. The authors nitrated mixtures of m- and p- nitrotoluenes (Table 61). 

The authors have determined the boiling point of trinitrotoluene at normal pressure by extrapolation and found it to be 300 10°C. The direct determination of the boiling point, is of course impossible, since it is near to the initiation temperature of the substance. 

A. J. B. Robertson [66] reported 345°C as the condensation temperature of trinitrotoluene vapours at 760 mm 1%, and 232°C at 30 mm Hg. Considering that the experimental conditions were difficult, it should be accepted that the results of all three workers are consistent. The value of 530°C, earlier determined by Menzies [67] by extrapolation of the results of vapour pressures measurements and heats of evaporation, is less probable. 

Vapour pressures of trinitrotoluene have been determined by several authors. The first measurements were carried out by Verola [68] between 1911 and 1912. He found a value of 25 mm Hg at 183°C and soon after attaining this temperature decomposition began. The evolution of gases causes the pressure to rise rapidly. The rate was as high as 20 mm Hg/min. 

However, trinitrotoluene reacts with alkalis, yielding organo-metallic products. The readiness of trinitrotoluene to react with alkalis has suggested the idea that it is an acid. This problem was studied by Fanner [75] in 1901. He applied a method, based on determining the partition coefficient K for trinitrotoluene between two liquid phases water and benzene or water and ligroin phase, with addition of sodium hydroxide to the water phase. 

Barbiere [145] examined quantitatively the process of sulphitation of a-, p-and y- trinitrotoluenes using a 6% solution of Na2S03 at different temperatures (30-60°C) and in another series of experiments the influence of the concentration of sodium sulphite solution on the solubility of the isomeric trinitrotoluenes at 30°C. He also determined ... 

This was determined by diluting the solution to hydrolyse the addition compounds. Precipitation of recovered a- trinitrotoluene gives the transient solubility (S3). By definition S2 = SrS3. 

In the context of chemical utilization of 2,4,6,-trinitrotoluene the different heterocyclic compounds including 3-chloro-4,6-dinitrobenzisothiazole [803], 2-aryl-4,6-dinitrobenzisothiazolium chlorides [804], etc. [805, 806] have been prepared and determined by NMR spectroscopy. 

The above mentioned disadvantages of PA are overcome by the introduction of trinitrotoluene (TNT). Pure 2,4,6-TNT was first prepared by Hepp (Fig. 1.3) and its structure was determined by Claus and Becker in 1883. In the early 20th century TNT almost completely replaced PA and became the standard explosive during WW I. TNT is produced by the nitration of toluene with mixed nitric and sulfuric acid. 

ESI is the most common interface since IPC and MS were coupled initially. By 2008, most applications IPC-MS used the ESI interface [58,68-82] because analytes amenable to IPC are usually already ionic in the column effluent that enters the interface. Examples of APCI-MS applications [83,84] include two-fold use of both interfaces [85] they gave similar results in the determination of polyunsatured fatty acid monoepoxides [86]. For determining mono- and di-sulfonated azo dyes, ESI proved to give the best performance in terms of sensitivity and reproducibility [83]. Joining negative APCI-MS and ESI-MS unambiguously identified several acidic oxidation products of 2,4,6-trinitrotoluene in ammunition, wastewater, and soil extracts [61]. 

Trinitrotoluene (also known as y-TNT) is one of the main impurities in military and commercial grades of TNT. Chick and Thorpe (1971) characterized two polymorphs. Form I (mp 376.2 K) may be obtained by recrystallization from alcohol or solidification of the melt. Form II (mp 347.2 K) is produced in small quantities with difficulty from an undercooled melt. It readily converts to Form I by mechanical perturbation or even spontaneously. Chick and Thorpe also determined latent heats of fusion, entropies of fusion, specific heats, IR spectra. Due to the conversion induced by grinding no X-ray data were presented for either form. No crystal structures have been reported. 

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