Thermo Scientific TSQ Quantum XLS, Руководство пользователя

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Introduction
Scan Modes
6 TSQ Quantum XLS Series User Guide Thermo Scientific
The mass analyzer or the mass spectrometer has three rod assemblies.
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The first and third rod
assemblies, Q1 and Q3, are quadrupoles, and the second rod assembly, Q2, is a square-profile
quadrupole.
Rod assemblies can operate in either of two capacities:
• As ion transmission devices
• As mass analyzers
If you apply only RF voltage, a rod assembly serves as an ion transmission device that passes
all ions within a large range of mass-to-charge ratios (that is, virtually all ions present).
When you apply both RF and dc voltages to a rod assembly, the separation of ions of different
mass-to-charge ratios occurs. This separation allows the rod assembly to serve as a mass
analyzer.
On the TSQ Quantum XLS Series mass spectrometers, the quadrupole rod assemblies can
operate with rf and dc voltages or with only rf voltage. That is, Q1 and Q3 can act either as
mass analyzers or ion transmission devices. The Q2 rod assembly operates exclusively with rf
voltage. As a result, Q2 is always an ion transmission device. Surrounding Q2 is a collision cell
where fragmentation can take place if the argon collision gas is present in the cell. For a
summary of how the rod assemblies function in several of the major scan modes, see
Table 1 .
.
a
Scan = full scan or transmission of selected ions
b
Pass all ions or fragments = pass ions or fragments within a wide range of mass-to-charge ratios
c
Set = set to pass ions of a single mass-to-charge ratio or a set of mass-to-charge ratios
d
Fragment ions = collisions with argon gas cause ions to fragment
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A rod assembly is a regular array of metal rods. For a discussion of the rod assemblies used on the
TSQ Quantum XLS Series instruments, see “Mass Analyzer” on page 31 .
Table 1. Summary of scan modes
Scan mode Q1 quadrupole Q2 collision cell Q3 quadrupole
Q1MS Scan
a
Pass all ions
b
Pass all ions
Q3MS Pass all ions Pass all ions Scan
Product Set
c
Fragment ions
d
, then pass all
fragments
Scan
Parent Scan Fragment ions, then pass all
fragments Set
Neutral loss Scan Fragment ions, then pass all
fragments Scan