Thermo Scientific TSQ Quantum GC, User Manual

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1
Introduction
Scan Modes
Thermo Scientific TSQ Quantum XLS and TSQ Quantum GC User Guide 9
Figure 3. Illustration of the Parent scan mode
Experiments that employ the parent scan mode (parent experiments) can be used in structure
and fragmentation studies as well as in survey analyses of mixtures. In general, parent
experiments detect all compounds that decompose to a common fragment. The experiments
are useful for the rapid detection of a series of structural homologs that have a common
fragment ion (for example,
m/z 149 for the phthalates).
Neutral Loss Scan Modes
In the Neutral Loss scan mode, the two mass analyzers (Q1 and Q3) are linked together so
that they are scanned at the same rate over mass ranges of the same width. The respective mass
ranges, however, are offset by a selected mass, such that the product mass analyzer scans a
selected number of mass units lower than the parent mass analyzer.
Thus, in the Neutral Loss scan mode, there are two stages of mass analysis. In the first stage,
the parent mass analyzer separates ions formed in the ion source by mass-to-charge ratio.
Then the ions are introduced sequentially into the collision cell.
In the second stage of analysis, ions admitted to the collision cell can fragment further by
metastable ion decomposition or by CID to produce product ions. The product mass analyzer
then separates these product ions by mass-to-charge ratio. Neutral Loss scan mode is
illustrated in
Figure 4 . Examples of compounds with a common neutral loss fragment appear
in Figure 5 .
Q2
RF Only + Ar
Q3 Set
Q1 m/z
Q1 Scanning