Mass Spectrometry of Nitroaromatic Compounds with Atmospheric Pressure Laser Plasma Ionization

The results of a study of the analytical characteristics of a mass spectrometric method based on atmospheric pressure laser plasma-induced ionization in the negative ion detection mode. The investigation focuses on the determination of 2,4-dinitrophenol, 2,5-dinitrophenol, 2-nitro-4-chlorophenol, 2,4-dichlorophenol, 2,4-dinitrotoluene, m-dinitrobenzene, and 3,3'-dinitrobiphenyl. Depending on their chemical properties, nitroaromatic compounds are ionized to form deprotonated molecules and/or molecular ions (radical anions). Calibration dependences for these compounds were plotted, and sensitivity coefficients were determined. The research demonstrates that sensitivity depends on the nature and position of substituents in the aromatic ring. The limits of detection for nitroaromatic compounds were estimated to be within the range 1–30 pg.