14N Nuclear Quadrupole Resonance Study of Polymorphism in Trinitrotoluene Samples Obtained from Old Ordnances

The field application of a ¹⁴N nuclear quadrupole resonance (NQR) detector needed for the detection of different explosives, including trinitrotoluene (TNT), requires the examination of the distribution of ¹⁴N NQR lines stemming from the monoclinic and/or orthorhombic modifications of TNT, as well as from a mixture of both. In this work, 30 different TNT samples up to 70 years old were measured. The main result of this study is that the measured ¹⁴N NQR spectrum is strongly influenced by the environmental conditions to which the explosive was subject during its history.