Mass spectrum
Fourier transform ion cyclotron resonance mass spectrometer
(FT-ICR-MS) was a kind of ultra-high resolving power, high accuracy
and superior performance of high speed scanning equipments
[6–10]. Positive electrospray ionization (ESI) formed hydrogen ion
during the spraying and evaporation process of the microdroplets,
and this process had received considerable study since the early
papers by Fenn et al. [11]. The positive ESI mass spectra collected
for this compound dissolved in methanol showed a major ion at
m/z 402.1822 corresponding to [M+H]+, with an error equal to
0.2 mDa from exact mass analysis.