1 research outputs found
Negative Ion Laser Desorption/Ionization Time-of-Flight Mass Spectrometric Analysis of Small Molecules Using Graphitic Carbon Nitride Nanosheet Matrix
Ultrathin
graphitic carbon nitride (g-C<sub>3</sub>N<sub>4</sub>) nanosheets
served as a novel matrix for the detection of small
molecules by negative ion matrix-assisted laser desorption/ionization
time-of-flight mass spectrometry (MALDI-TOF MS) was described for
the first time. In comparison with conventional organic matrices and
graphene matrix, the use of g-C<sub>3</sub>N<sub>4</sub> nanosheet
matrix showed free matrix background interference and increased signal
intensity in the analysis of amino acids, nucleobases, peptides, bisphenols
(BPs), and nitropolycyclic aromatic hydrocarbons (nitro-PAHs). A systematic
comparison of g-C<sub>3</sub>N<sub>4</sub> nanosheets with positive
and negative ion modes revealed that mass spectra produced by g-C<sub>3</sub>N<sub>4</sub> nanosheets in negative ion mode were featured
by singly deprotonated ion without matrix interference, which was
rather different from the complicated alkali metal complexes in positive
ion mode. Good salt tolerance and reproducibility allowed the determination
of 1-nitropyrene (1-NP) in sewage, and its corresponding detection
limit was lowered to 1 pmol. In addition, the ionization mechanism
of the g-C<sub>3</sub>N<sub>4</sub> nanosheets as matrix was also
discussed. The work expands its application scope of g-C<sub>3</sub>N<sub>4</sub> nanosheets and provides an alternative approach for
small molecules