Ionization behaviors of nitrotoluenes and dinitrotoluenes by reactions with acetone ‐related reactant ion

In this study, ionization behaviors of NT (2-, 3-, and 4-NTs) and DNT isomers (2,3-, 2,4-, and 2,6-DNTs) by reactions with [2Acetone  + O2]•− were investigated. The energy-minimized structures of the product ions and their energies were calculated to explain the differences in the ionization behaviors. Typical NT- and DNT-related ions were produced by reactions with [2Acetone  + O2]•−; NT•−, [NT – H]−, DNT•−, [DNT – H]−, and [DNT – NO]− ions. The ionization efficiencies of NT- and DNT-related ions increased by increasing the source fragmentor voltage, and those of DNT-related ions were higher than those of the NT-related ions owing to the presence of an additional nitro group. The ionization efficiency of 3-NT•− was higher than that of [NT – H]−, while that of [DNT – H]− was higher than those of DNT•− and [DNT – NO]−. The ionization efficiency order of NT•− was 3-NT  >  4-NT >  2-NT, while that of [DNT – H]− was 2,4-DNT  >  2,6-DNT >  2,3-DNT. The [NT – H]− and [DNT – H]− ions were stabilized by resonance structures containing nitro groups. The [DNT – NO]− ions were formed through the transition state.
Source: Journal of Mass Spectrometry - Category: Chemistry Authors: Tags: RESEARCH ARTICLE Source Type: research