Nitrotoluenes analysis

For onsite analysis, the examination of the vast number of samples necessitates the use of quick, reliable, field portable equipment that can rapidly, quantitatively verify the many chemically different types of ammunition, explosives, and pyrotechnics. The most common suite of analytes to detect is large, consisting of very chemically different compounds and usually occurs at trace levels in complex environmental matrices. This suite encompasses smokeless powders, black powders, and numerous propellant and energetic formulations. Detection should also be sought for common decomposition products of these explosives such as the methylanalines, aminonitrotoluenes, nitrotoluenes, mono- and dinitoroglycerines, and the nitrobenzenes under on-site conditions. 

Fig. 3.61. HPLC-UV chromatogram at 230 nm for the analysis of the aromatic amines listed. (1) 1,4-Diaminobenzene (2) 2-chloro-l,4-diaminobenzene (3) 2,4-diaminotoluene (4) benzidine (5) 4,4 -oxidianiline (6) aniline and 4-nitroaniline (7) o-toluidine (8) 4,4 -methylenedianiline (9) 3,3 -dimethoxibenzidine (10) 3,3 -dimethylbenzidine (11) 4-chloroaniline and 2-amino-4-nitrotoluene (12) 4,4 -thiodianiline (13) p-cresidine (14) 2,4-dimethylaniline (15) 2-naphty-lamine (16) 4-chloro-o-toluidine (17) 4,4 -methylene-di-o-toluidine (18) 2,4,5-trimethylaniline (19) 4-aminobiphenyl (20) 3,3 -dichlorobenzidine (21) 4,4 -methylenbis (2-chloroaniline) and (22) o-aminoazotoluene. Reprinted with permission from M. C. Garrigos et al. [130].

The investigation of viscosities, electrical conductivities, refractive indexes and densities of binary liquid systems of sulphuric acid with nitromethane, nitrobenzene and 0-, m and p-nitrotoluene was made in order to obtain a clearer picture of the behaviour of these binary mixtures, regarding the stability of the addition compounds formed between the components. The application of these methods of physicochemical analysis to a number of binary systems with sulphuric acid [1, 2, 3] has enabled us to get some idea of the way in which the formation and stability of addition compounds affects the liquid phase properties of these systems. The binary systems of sulphuric acid with mononitrocompounds are particularly suitable for comparison with each other, because of the close similarity of the liquid media in these systems, due to comparable values of dielectric constants and liquid phase properties of the mononitrocompounds. The stability of the addition compounds in these systems in the crystalline phase [4] has... 

CST may be used for analysis, especially to estimate water in alcohols or other liquids, since CST is often very sensitive to traces of water or other impurities (79-81, 220-223). Mixtures of n-butane and isobutane were analyzed easily and quantitatively by CST with o-nitrotoluene (141). 

Fig. 4. Example of thermal energy analyser (TEA) standard analysis using CPSIL-19 column type. EGDN, Ethylene glycol dinitrate FNT, 2-fluoro-5-nitrotoluene MT, musk tibetine NB, nitrobenzene NG, nitroglycerine PETN, pentaerythritol tetranitrate and RDX, cyclotrimethylene trinitramine TNT, trinitrotoluene. Reprinted with permission from Warren et al. [46], Copyright (1999) Forensic Science Society.

R. M. Roberts, Browder, and Kobe [10] carried out a number of experiments using isotope dilution analysis to determine the proportion of m- nitrotoluene formed in the course of nitration of toluene. 

The retrosynthetic analysis has provided two valid routes from benzene to 4-bromo-2-nitrotoluene. 

Detection and identification of chemical warfare simulants based on multidimensional phase shaped femtosecond laser pulses coupled to mass spectrometry (MS) is demonstrated. The presented approach is based on binary phase shaping (BPS) and aims to improve the accuracy and precision required for security applications. It is based on multiphoton intrapulse interference of femtosecond laser pulses. Spectra retrieved by applying n-differently shaped pulses represent n-dimensions of the analysis. We present a multidimensional technique for detection and identification of analogues to chemical agents and mixtures in real-time. Experimental results for dimethyl phosphate, pyridine, and three isomers of nitrotoluene are presented. 

The mass spectrum of o-nitrotoluene shows a substantial peak at m/z 120. Similar analysis of a,a,a-tri-deutero-o-... 

For the retrosynthesis of indole (see Fig. 5.8), two routes (I/II) are proposed, as for pyrrole (see p 94). Route I suggests o-aminobenzyl ketone 1 or 6>-alkyl-A -acylaniline 2 as starting material on the basis of operations a - c. Their retroanalysis (d,e) in turn leads to 2-alkylaniline 5 and carboxylic acid derivative 6. Construction of the indole system should thus occur by N- or C-acylation of 5 (utilizing the o-nitrotoluene derivative 4) followed by cyclodehydration of 1/2. The alternative route n, based on retrosynthetic analysis g-i, leads to aniline via the a-(A -phenylamino)ketones 3 and to a-halo ketones 7 as possible precursors for the indole synthesis. 

In addition to the reaction schemes described earlier, there are many other types of systems that are quite common. In one of these, a single reactant may be converted into several different products simultaneously. There are numerous examples of such reactions in organic chemistry. For example, the reaction of toluene with bromine in the presence of iron at 25°C produces 65% p-bromotoluene and 35% o—bromotoluene. Similarly, the nitration of toluene imder different conditions can lead to different amounts of o—nitrotoluene and p-nitrotoluene, but a mixture of these products is obtained in any event. Tailoring the conditions of a reaction to obtain the most favorable distribution of products is a common practice in synthetic chemistry. We will now illustrate the mathematical analysis of the kinetics of such reactions. 

Total acidity of the samples was determined by the reverse titration using n-butylamine solution in cyclohexane with bromthymol blue as an indicator. The strength of acid sites was estimated by direct titration with n-butylamine using Hammett indicators (Aldrich) benzalacetophenone (pKbh = -5.6), antraquinone (-8.2), 4-nitrotoluene (-11.35), l-chloro-3-nitrobenzene (-13.16), 2,4-dinitrotoluene (-13.75) and 2, 4-dinitro-l-fluorobenzene (-14.52). All samples were dried at 500°C, Ih before testing. XRD patterns of samples were recorded on DRON-4-07 diffractometer (CuKa radiation). Surface areas, pore size distributions and pore volumes were measured by N2 adsorption at 77 K using Nova 2200e Smface Area and Pore Size Analyzer. Before analysis, the samples were treated at 300°C under vacuum. 

This is another case of an unexpected finding by GC/MS not likely to have been learned otherwise. A polyethylene (PE) laboratory waste container exploded. GC/MS was done on a fragment of recovered PE. Fig. 7 [2] shows toluene, nitrotoluene and dinitrotoluene. There was also an indication of trinitrotoluene TNT. The explosion oceurred because two people were putting in the waste container toluene in one case and nitric acid in the other. Over time the two compounds reacted and when the TNT accumulated to an explosive level, there was an explosion. Without GC/MS it might not have been known why the explosion occurred. This is not a case of plastics failure in the usual sense. Nevertheless, analysis of the plastic revealed the cause of an explosion in which plastic was involved. 

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