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UBC Theses and Dissertations
A new linear ion trap time of flight instrument with tandem mass spectrometry capabilities Campbell, Jennifer Mary
Abstract
This thesis summarizes the construction and characterization of a novel hybrid mass spectrometer with tandem mass spectrometry capabilities, named the linear ion trap time of flight mass spectrometer. In a "linear ion trap" ions are trapped in a 2-dimensional quadrupolar potential by the application of timed stopping potentials on entrance and exit apertures. The performance characteristics of the linear ion trap as a storage device are initially assessed using a modified triple quadrupole mass spectrometer. On the time scales for tandem mass spectrometry, injection, extraction, and trapping efficiencies are all near 100%. The modified operation of the triple quadrupole mass spectrometer is used to study the kinetics of dissociation of gas phase holomyoglobin in high charge states. The results indicate that the binding of the heme group is relatively unaffected by intramolecular repulsion resultant from excess charge. To construct the linear ion trap time of flight mass spectrometer, a linear ion trap is orthogonally coupled to a linear time of flight mass analyzer. The mass resolutions of the spectrometer could be optimized to attain resolutions near 700. Tandem mass spectrometry in the linear ion trap is enabled by superimposing a dipolar excitation voltage on the quadrupolar field by coupling an auxiliary waveform generator to a pair of the quadrupole rods. This voltage is used to effect precursor isolation via a broadband waveform followed by collision induced dissociation through mass selective resonant excitation. The resulting fragment ions are detected in the time of flight mass spectrometer. With 7 mTorr N 2 as the collision gas, the resolutions of ion isolation and excitation are ~ 40 and 70, respectively. Fragmentation efficiency is near 60 %. When a lower pressure is used, the same resolutions increase to 100 and 250, respectively. It is found that the resolution of resonant excitation is strongly dependent upon amplitude of the applied voltage.
Item Metadata
Title |
A new linear ion trap time of flight instrument with tandem mass spectrometry capabilities
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Creator | |
Publisher |
University of British Columbia
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Date Issued |
1999
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Description |
This thesis summarizes the construction and characterization of a novel hybrid
mass spectrometer with tandem mass spectrometry capabilities, named
the linear ion trap time of flight mass spectrometer. In a "linear ion trap"
ions are trapped in a 2-dimensional quadrupolar potential by the application
of timed stopping potentials on entrance and exit apertures. The performance
characteristics of the linear ion trap as a storage device are initially
assessed using a modified triple quadrupole mass spectrometer. On the time
scales for tandem mass spectrometry, injection, extraction, and trapping efficiencies
are all near 100%. The modified operation of the triple quadrupole
mass spectrometer is used to study the kinetics of dissociation of gas phase
holomyoglobin in high charge states. The results indicate that the binding of
the heme group is relatively unaffected by intramolecular repulsion resultant
from excess charge.
To construct the linear ion trap time of flight mass spectrometer, a linear
ion trap is orthogonally coupled to a linear time of flight mass analyzer. The
mass resolutions of the spectrometer could be optimized to attain resolutions
near 700. Tandem mass spectrometry in the linear ion trap is enabled by superimposing
a dipolar excitation voltage on the quadrupolar field by coupling
an auxiliary waveform generator to a pair of the quadrupole rods. This voltage
is used to effect precursor isolation via a broadband waveform followed
by collision induced dissociation through mass selective resonant excitation.
The resulting fragment ions are detected in the time of flight mass spectrometer.
With 7 mTorr N 2 as the collision gas, the resolutions of ion isolation
and excitation are ~ 40 and 70, respectively. Fragmentation efficiency is near
60 %. When a lower pressure is used, the same resolutions increase to 100
and 250, respectively. It is found that the resolution of resonant excitation
is strongly dependent upon amplitude of the applied voltage.
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Extent |
10543434 bytes
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Genre | |
Type | |
File Format |
application/pdf
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Language |
eng
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Date Available |
2009-07-02
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Provider |
Vancouver : University of British Columbia Library
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Rights |
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.
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DOI |
10.14288/1.0061530
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URI | |
Degree | |
Program | |
Affiliation | |
Degree Grantor |
University of British Columbia
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Graduation Date |
1999-11
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Campus | |
Scholarly Level |
Graduate
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Aggregated Source Repository |
DSpace
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Item Media
Item Citations and Data
Rights
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.