Thermo Scientific TSQ Series Hardware Manual page 20

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Introduction
The TSQ instrument's triple-stage mass analyzer performs either one or two stages of mass analysis:
• The TSQ system is operated as a conventional mass spectrometer with one stage of mass
• The TSQ system is operated as a tandem mass spectrometer with two stages of mass analysis.
In a first stage of mass analysis the TSQ systems can be used to elucidate the structures of pure
organic compounds and the structures of the components within mixtures. Furthermore, in a
second stage of mass analysis, the mass spectrometer can fragment and separate each ionic fragment
of a molecule formed in the ion source to build up an entire structure for the molecule, piece by
piece. Thus, TSQ systems make investigating all pathways for the formation and fragmentation of
each ion in the mass spectrum possible.
The two stages of mass analysis, with resultant reduction of chemical noise in the final mass
spectrum, allow for very selective and sensitive analysis.
Each sequence of single- or triple-stage mass analysis of the ions is called a scan. The TSQ mass
spectrometer uses several different scan modes and different scan types to filter, fragment, or
transmit ions in the mass analyzer. Along with the ionization and ion polarity modes, the ability to
vary the scan mode and scan type affords the user great flexibility in the instrumentation for
solving complex analytical problems.
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The instrument can also be used as a single-stage mass spectrometer by transmitting the ions through the first and
second rod assemblies followed by mass analysis in the third rod assembly.
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analysis. The ion source ionizes the sample and the ion products are subjected to mass analysis
in the first rod assembly. The second and third rod assemblies transmit the resulting
mass-selected ions to the ion detection system.
The ion source ionizes the sample and the ion products are mass analyzed by the first rod
assembly. In this case, however, mass-selected ions exiting the first rod assembly collide with an
inert gas in the second rod assembly and fragment to produce a set of ions known as product
ions. (A chamber called the collision cell surrounds the second rod assembly. The collision cell
can be pressurized with an inert gas.) The product ions undergo further mass analysis in the
third rod assembly to detect selected ions. Two stages of mass analysis yield far greater chemical
specificity than a single stage can achieve, because of the system's ability to select and
determine two discrete but directly related sets of masses.
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