Thermo Scientific TSQ Altis, Руководство по оборудованию

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152 TSQ Altis, Quantis, and Fortis Hardware Manual Thermo Scientific
RF lens A multipole rod assembly that is operated with only radio frequency (RF) voltage on
the rods. In this type of device, virtually all ions have stable trajectories and pass through the
assembly.
RF voltage (linear ion trap) An AC voltage of constant frequency and variable amplitude
that is applied to the quadrupole rods of a multipole. Because the frequency of this AC
voltage is in the radio frequency (RF) range, it is referred to as RF voltage.
S
scan Comprised of one or more microscans. Each microscan is one mass analysis (ion
injection and storage/scan-out of ions) followed by ion detection. After the microscans are
summed, the scan data is sent to the data system for display and/or storage. The process of
ramping the amplitude of the RF and DC voltages on the multipole rods in the mass
analyzer to transmit ions from the lowest mass to the highest mass of a specified scan range.
selected ion monitoring (SIM) scan type A scan type where the mass spectrometer acquires
and records ion current following the isolation of a range of mass-to-charge ratio values.
selected reaction monitoring (SRM) scan type A scan type with two stages of mass analysis
and where a particular reaction or set of reactions, such as the fragmentation of an ion or the
loss of a neutral moiety, is monitored. In SRM a limited number of product ions is
monitored.
sheath gas The inner coaxial gas (nitrogen), which is used in the API source to help nebulize
the sample solution into a fine mist as the sample solution exits the ESI or APCI nozzle.
signal-to-noise ratio (S/N) The ratio of the signal height (S) to the noise height (N). The
signal height is the baseline corrected peak height. The noise height is the peak-to-peak
height of the baseline noise.
sweep gas Nitrogen gas that flows out from the gap between the sweep cone and the ion
transfer tube into the API source. Sweep gas aids in solvent declustering and adduct
reduction.
syringe pump A device that delivers a solution from a syringe at a specified rate.
T
turbomolecular pump A vacuum pump that provides a high vacuum for the mass
spectrometer and detector system.
V
vacuum manifold A thick-walled, aluminum chamber, with various electrical feedthroughs
and gas inlets, which encloses the API stack, ion optics, mass analyzers, and ion detection
system.