
Exploring PSD Mode
Voyager
™
Biospectrometry
™
Workstation User’s Guide 7-47
7
6. Check the Grid Voltage% setting in the standard .BIC file
provided on your system for angiotensin I
(Angiotensin_Reflector.BIC). Acquire a spectrum using
this setting. At this setting, you should observe optimum
resolution on the high mass peak.
7.4.4 Summary
The table below summarizes the impact of changing PSD
acquisition conditions.
Condition Impact
Laser
intensity
• Increase higher than normal to induce fragmentation.
• Setting too high increases baseline noise and eventually
decreases signal.
• Setting too low reduces fragment ion abundance.
Precursor Ion
Selector
• Turn on to eliminate fragments that do not travel with the
selected precursor mass.
• Decrease the Deflector Gate Width (set in Hardware
Configuration) to narrow the Precursor Ion Selector mass
window.
• Extremely small Deflector Gate Widths can weaken fragment
ion intensity.
Grid
Voltage%
• Increase or decrease to affect the focus of fragment ions.
• Higher Grid Voltage% settings shift the optimal focus toward
shorter flight times (lower masses within a PSD segment).
Guide Wire
Voltage%
• Decreasing the Guide Wire Voltage% with lower Mirror Ratio
settings may or may not improve the quality of PSD data.
• Avoid using Guide Wire Voltage% settings above 0.02%.
Higher settings may compromise the selectivity of the
Precursor Ion Selector.
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