Characterization of a Series of Nitrogen-Rich Molecules using Laser Induced Breakdown Spectroscopy

A series of nitrogen-rich molecules, such as 5-aminotetrazolium nitrate (HAT-NO3) and hydrazinebistetrazole (HBT), bis(2,2,2-trinitroethyl)-hydrazodicarboxylate (BTHC), cyclotrimethylene trinitramine (RDX), trinitrotoluene (TNT), melamine, sucrose, and L-glutamine were studied using laser-induced breakdown spectroscopy (LIBS). The atomic emission intensities and intensity ratios of the constituent elements from the LIBS spectrum were shown to correlate with the mole fractions and stoichiometries of the molecules. In addition, the amount of oxygen present in the molecule influenced the emission intensities of molecular fragments such as C-2. Finally, we used principal components analysis to analyze the data from the LIBS spectra and separate the different organic molecules based on the atomic emission intensities and ratios.