HP Data Explorer 4 Series - Manual (Page 225)

Manual Calibration
Data Explorer ™ Software User’s Guide 5-21
5
3. To modify an entry, click the entry to select it, modify the
entry as needed, then click Update.
4. To delete an entry, click the entry to select it, then click
Delete.
5. To add an entry, type the Name and Theoretical m/z for a
reference compound, then select the charge state.
Optionally, enter the Elemental Composition for the
compound.
6. Specify the mass type (Resolved Isotope or Average).
7. Click Insert.
CAUTION
The software allows you to add multiple items with the
same m/z value to the calibration list box if any other
attribute of the reference compound is different (for
example, charge state or name). Each mass in the list
is considered during calibration. If the mass list
contains duplicate entries, the calibration may return an
invalid number of matches.
8. Click Save or Save As.
9. In the Save As dialog box, select a location and type a
name for the file, then click Save.
Specifying mass
type for highly
charged, narrow
peaks
When specifying highly charged, non-isotopically resolved
species with peaks less than 1 Da wide (for example,
myoglobin +20) as reference masses in a calibration reference
file, set the peak type as a Resolved Isotope Mass (even
though it is not a resolved isotope). The calibration routine
checks peak width to determine if a peak matches a Resolved
Isotope Mass or an Average mass. If narrow peaks are
specified as Average Masses in the calibration reference file,
the software mistakes these narrow peaks as isotopically
resolved and ignores the reference mass.