Purification of 2,4,6-trinitrotoluene by digestion with sodium sulfite and determination of its impurities by gas chromatography–electron capture detector (GC-ECD)

Investigation of Physical and Chemical Properties of TNT after Spray Drying

“…The AR (AR) TNT sample has the most and highest concentration of impurities among the samples, as expected. These impurities mostly consist of synthesis impurities for TNT including 2,4,5-trinitrotoluene, 1,3-dinitrobenzene (DNB), 2,4-dinitrotoluene (DNT), 3,5-DNT, 1,3,5-trinitrobenzene, 2,4,6-trinitrobenzenesulfonic acid, 2,4,6-trinitro-1-ethylbenzene, and N -(methylideneamino)-2,4-dinitroaniline. − We observe that there is some purification of TNT by spray drying (AR-SD), where the lower boiling point impurities are reduced, including DNB, DNT, and 3,5-DNT. However, many of the other synthesis impurities from the crude TNT starting material remain after spray drying.…”

“…The existence of multiple isomers has been determined through characterization and synthesis to understand synthesis impurities. , Polymorphism of TNT was a more complex issue that took much longer to solve as the polymorph occurs from the rotation and stacking of TNT molecules in the unit cell. It has been shown that TNT has a stable monoclinic phase ( P 12 1 / a 1) and a less stable orthorhombic phase ( Pca 2 1 ). − Polymorphism plays an important role in understanding HE material properties, such as sensitivity to accidental stimuli, density, sensitivity to shock initiation, and power. , Many synthesis impurities have been identified, which have to be removed from crude TNT before use in applications. − Because of the synthesis impurities and the importance of polymorphism, controlled synthesis of TNT with desired chemical and structural properties as well as purification of crude TNT have been studied in detail. − Controlled synthesis has also proven to be important for the future of TNT, as traditionally used purification techniques leave behind polluted waste water, known as “red water”. , …”

“…This agrees with previous studies that have shown TNT follows that Ostwald’s rule of stages, where the less stable polymorph crystallizes first. , We also investigated the purity of each sample of TNT prepared by the various methods. The synthesis impurities of TNT have been previously identified. − Although we observed that spray drying alone is able to remove some of the low boiling point synthesis impurities of TNT, we determined that it is necessary to perform a recrystallization step before spray drying in order to produce a high-purity TNT powder.…”

Investigation of different alcoholic modifiers for the separation and determination of two isomers of dinitrotoluene (2,4 and 2,6) by ion mobility spectrometry

“…This sample was collected from the Iranian Defense Industry (Zarrinshahr, Isfahan). The samples contained some impurities such as 2,4‐ and 2,6‐DNT and also sulfonic acid salts (other impurities were ultra‐trace and so not detectable by IMS) 20 . The concentrations of the analytes were very high so the solution was diluted 1:100 with distilled water prior to analyte extraction to reduce the matrix interferences.…”

Detection of TNT wastewater by the molecular imprinted porous membrane

“…Figure 1 shows the molecularly imprinted TNT porous film prepared by the design scheme in this paper. After the removal of the initial TNT template molecule, the imprinted cavity is left with covalently fixed amine groups on the cavity wall [5][6][7] .…”