HP Data Explorer 4 Series - Manual (Page 107)

Peak Detection
Data Explorer ™ Software User’s Guide 3-9
3
• Deisotope (reflector data only)—Peak
deisotoping reduces the spectrum to a
monoisotopic centroided plot of the monoisotopic
masses. This is useful in identifying overlapping
isotope clusters. Make sure peak detection
thresholds are set low enough to detect the
monoisotopic peak before deisotoping. For more
information, see Section 3.4, Deisotoping a
Spectrum. Deisotoping provides no benefit on linear
data (non-isotopically resolved) or on PSD data
(pure isotope data).
3. If peak detection is not acceptable, keep the Use
Resolution Dependent Settings option enabled, and
adjust the parameter associated with the observed
problem:
Problem Suggested Actions
High-mass peaks not
detected Decrease Mass Resolution setting. The default Mass
Resolution settings are optimized for masses below
20,000 Da.
Noise detected as peaks Increase the %Max Peak Area.
Decrease the Resolution.
Peaks of interest are not
detected Decrease the %Max Peak Area.
NOTE: %Max Peak Area is calculated above the local
baseline and can compensate for problems related to a
rising global baseline.
Low Mass Gate spike is
identified as the Base
Peak Truncate the data to eliminate the Low Mass Gate spike,
then reapply peak detection settings. See Section 5.9,
Truncating a Spectrum.
Peaks detected before
deisotoping are not
detected after
deisotoping Set %Max Peak Area and %BP Intensity to 0 before
deisotoping, deisotope, then reset thresholds to
appropriate settings after deisotoping.