Glossary: heated-electrospray (H-ESI)
Thermo Scientific Orbitrap Fusion Series Hardware Manual 93
H
heated-electrospray (H-ESI) Converts ions in
solution into ions in the gas phase by using
electrospray (ESI) in combination with heated
auxiliary gas.
higher energy collision-induced dissociation
(HCD) Collision-induced dissociation that occurs in
the ion-routing multipole (IRM). The IRM consists
of a straight multipole mounted inside a collision
gas-filled tube. A voltage offset between the C-trap
and IRM accelerates parent ions into the collision gas
inside the IRM, which causes the ions to fragment
into product ions. The product ions are then sent to
the ion trap or the Orbitrap mass analyzer for mass
analysis. HCD produces triple quadrupole-like
product ion mass spectra.
I
image current detection The detection of ion motion
by the charge (current) induced on one or more
capacitive plates (outer electrodes).
ion detection system A high sensitivity, off-axis
system for detecting ions. It produces a high signal-
to-noise ratio (S/N) and allows for switching of the
voltage polarity between positive ion and negative
ion modes of operation. The ion detection system
includes two ±12 kVdc conversion dynodes and a
discrete dynode electron multiplier.
ion isolation A step in the quadrupole Q1 or linear
ion trap mass analysis where the mass analyzer ejects
all ions except for the ions of interest.
ion isolation waveform voltage A waveform applied
to the linear ion trap that ejects all ions except the
SIM ion or precursor ion.
ion optics Focuses and transmits ions from the API
source to the mass analyzer.
ion polarity mode The mass spectrometer can operate
in either of two ion polarity modes: positive or
negative.
ion sweep cone A removable cone-shaped metal cover
that fits on top of the API ion transfer tube and acts
as a physical barrier to protect the entrance of the
tube.
ion-routing multipole The collision cell where higher
energy collision-induced dissociation (HCD) takes
place.
L
lens A metal disk with a circular hole in the center that
allows the ion beam to pass.
M
make-up gas The gas associated with the optional
EASY-IC or EASY-ETD ion source assembly that
flows from the mass flow controller to the reagent
distribution assembly.
mass analysis A process that produces a mixture of
ionic species that is then separated according to the
mass-to-charge ratios (m/z) of the ions to produce a
mass spectrum.
mass analyzer A device that determines the mass-to-
charge ratios (m/z) of ions by one of a variety of
techniques.
mass analyzer DC offset voltage A DC voltage that is
applied to the mass analyzer electrodes to help draw
ions in from the ion optics. This voltage defines the
translational kinetic energy of the ions as they enter
the mass analyzer. For the mass detector, the mass
analyzer DC offset voltage is –10 Vdc for positive
ions and +10 Vdc for negative ions.
mass spectrometer An instrument that ionizes sample
molecules and then separates the ions according to
their mass-to-charge ratio (m/z). The resulting mass
spectrum is a characteristic pattern for the
identification of a molecule.
mass spectrum A graphical representation (plot) of
measured ion abundance versus mass-to-charge ratio.
The mass spectrum is a characteristic pattern for the
identification of a molecule and is helpful in
determining the chemical composition of a sample.
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