Applied Biosystems Data Explorer 4 Series User Manual page 131

Max Charge State
and Max Isotope #
set correctly
Max Charge State
set too low
When the Max Charge State and Max Isotope # are set
correctly (in the example shown in Figure 3-7, both are set
to 4), the neurotensin 558 m/z isotope cluster contains four
peaks at charge state 3. Peaks are 0.33 m/z apart
(Figure 3-7).
Figure 3-7 Max Charge State and Max Isotope # Set
Correctly for Neurotensin
When the Max Charge State is set too low, the charge state for
all peaks may not be correctly determined. In this example
with the Max Charge State set to 2, only the first and fourth
peaks are labeled with charge states (Figure 3-8 on
page 3-34). This is because the software:
• Checks for peaks at 0.5 m/z from each peak (charge
state 2 evaluation).
• Finds no peaks and checks for peaks at 1 m/z from each
peak (charge state 1 evaluation).
• Finds one peak pair at 558.3 m/z and 559.3 m/z and
labels these peaks as charge state 1.
• Does not find a match for peaks at 558.6 m/z or 558.9
m/z, so these peaks are considered to have no calculated
charge, and are not labeled with a charge state
(Figure 3-8 on page 3-34).
Data Explorer
Peak Detection
™
Software User's Guide
3
3-33