Antec Scientific ROXY Exceed, User Manual, Page: 83 / 126

Chapter 7 Optimization of working potential 83
On-line electrochemistry mass spectrometry
Information about potential optimization for ROXY EC system and the
detailed background information about the supplied events files and
relevant Dialogue settings are provided in the application note
210.001A ROXY™ EC system – events programming & settings
ROXY EC system delivers the oxidative metabolic fingerprint of the mole-
cule in a very short time. The acquired mass spectra can be presented in
three-dimensional plots, so-called MS voltammograms (Fig. 40). A MS
voltammogram visualizes the ion abundance versus m/z as a function of
applied potential to the electrochemical cell. With a mass voltammogram
the optimal potential can be determined for electrochemical generation of
the desired metabolite for further research, e.g., NMR.
In the figure 21, the 3-D MS voltammogram of amodiaquine is shown. To
oxidized Amodiaquine to get dehydrogenated metabolite it is required to
use lower (400mV) potential than to form to other metabolites (m/z 299
and 326) and in this case the potential should be ca. 1200mV. For each
cell potential mass spectra are recorded and saved in separate data files.
Fig. 42. 3-D MS Voltammogram of Amodiaquine. The plot is reconstructed
from the separate mass spectra saved for each potential value.