Quattro 2 User's Guide, issue 2. 6666533 - Waters

Quattro II
User's Guide
Setting Up for MS-MS Operation
The following notes provide a worked example for the acquisition of daughter ion
data. The experiment is performed in the EI positive mode using heptacosa (FC43) as
a model analyte. Heptacosa, admitted from the reference inlet, provides a stable and
persistent source of ions for instrument tuning in both the MS and MS-MS modes of
operation.
The basic tuning and optimisation principle demonstrated below (with heptacosa) may
be applied in other ionisation modes simply by substituting an appropriate persistent
source of ions. For example, in the FAB mode, caesium iodide or glycerol matrix
peaks may be used. In thermospray or API, solvent background peaks may be used.
The basic sequence of events is as follows:
• Tuning MS1.
• Tuning MS2.
• Parent ion selection.
• Fragmentation.
Tuning MS1 and MS2
These two procedures have been described earlier in this chapter
Parent Ion Selection
For maximum sensitivity in daughter ion analysis the centroid of the parent ion
selected by MS1 must be accurately found.
The nominal mass of the parent is first determined (if unknown) by viewing it at the
first detector (MS1):
Set up a 1 box display in the tune page and set Function to MS. Observe the
candidate parent ion in the tune display and determine its nominal mass.
In this example the heptacosa ion atz219 will be used as a model parent.
Routine Procedures
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