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148
TSQ Altis, Quantis, and Fortis Hardware Manual
Thermo Scientific
C
centroid data
Data used to represent mass spectral peaks in terms of two parameters: the
centroid (the weighted center of mass) and the intensity. The data is displayed as a bar
graph. The normalized area of the peak provides the mass intensity data.
charge state
The imbalance between the number of protons (in the nuclei of the atoms) and
the number of electrons that a molecular species (or adduct ion) possesses. If the species
possesses more protons than electrons, its charge state is positive. If it possesses more
electrons than protons, its charge state is negative.
collision energy
The energy used when ions collide with the collision gas.
collision gas
A neutral gas used in the collision cell to undergo collisions with ions.
collision-induced dissociation (CID)
A method of fragmentation where ions are
accelerated to high-kinetic energy and then allowed to collide with neutral gas molecules
such as helium. The collisions break the bonds and fragment the ions into smaller charged
product ions and neutral fragments.
contact closure connection
The cable connection is from the external peripheral device to
the mass spectrometer contact closure pins (Start In and Ground). The external device
sends the contact closure (start) signal to the mass spectrometer.
conversion dynode
A highly polished metal surface that converts ions from the mass
analyzer into secondary particles, which enter the electron multiplier.
D
divert/inject valve
A valve on the mass spectrometer that can be plumbed as a divert valve or
as a loop injector.
E
electron multiplier
A device used for current amplification through the secondary emission
of electrons. Electron multipliers can have a discrete dynode or a continuous dynode.
electrospray (ESI)
A soft ionization technique operating at atmospheric pressure. Ions are
generated in solution and a high voltage is applied to generate small droplets that are then
evaporated until all ions are in the gas phase.
F
flow rate, syringe pump status
The syringe pump injection flow rate in milliliters per
minute (mL/min) or microliters per minute (μL/min) for the current sample, as defined in
the current experiment method.