A GC-MS Database of Nitrogen-Rich Volatile Compounds

Unsymmetrical dimethylhydrazine (UDMH) was previously used as a rocket propellant in launch vehicles. During the operation and accidents of launch vehicles, hundreds of tons of UDMH were released. While these launch vehicles are gradually being phased out, UDMH continues to be used in space technology and other industries. When released into the environment, UDMH forms numerous transformation products. Several dozen have been reliably identified, and hundreds are believed to exist, many of which are highly toxic and quite persistent in the environment. Gas chromatography–mass spectrometry (GC-MS) is one of the primary methods for identifying these compounds. Library searches using mass spectra and retention indices are often used. However, UDMH transformation products are highly specific—they are organic compounds, typically aromatic heterocycles, with unusually high nitrogen content. Such compounds are poorly represented in GC-MS databases, while existing data are often of poor quality and were obtained back in the 1980s. A database of such compounds was presented, containing information on retention indices for non-polar (5%-phenylpolydimethylsiloxane) and polar (polyethylene glycol) stationary phases, as well as electron ionization mass spectra (70 eV) for 104 nitrogen-containing compounds: derivatives of triazoles, pyrazoles, imidazoles, pyridines, diazines, and triazines, as well as amides and other compounds. Many of the compounds presented in the database are proven UDMH transformation products, while many of the other compounds are probable. Derivatives of triazoles and triazines are also used as pesticides, and our database can be useful in detecting their derivatives. The database is free and available online.