Thermo Scientific Orbitrap Fusion Lumos Getting Started Manual page 109

I
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 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.
isolation window The baseline width of a window for
a mass peak (or peak cluster) of interest for an
n
MS/MS or MS scan.
ion-routing multipole The collision cell where higher
energy collision-induced dissociation (HCD) takes
place.
ion source See API source.
L
lens An element that provides focusing of the ion
beam.
M
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.
Thermo Scientific
mass spectrometer An instrument that ionizes sample
molecules and then measures and analyses the ions
according to their mass-to-charge ratio (m/z). The
resulting mass spectrum is a characteristic pattern for
identifying 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.
mass-to-charge ratio (m/z) An abbreviation used to
denote the quantity formed by dividing the mass of
an ion (in Da) by the number of charges carried by
the ion. For example, for the ion C7H7
m/z = 45.5.
molecular ion An ion formed by the removal (positive
ion) or addition (negative ion) of one or more
electrons to/from a molecule without fragmentation
of the molecular structure.
MS scan modes Scan modes where only one stage of
mass analysis is performed. The scan types used with
the MS scan modes are full-scan type and selected
ion monitoring (SIM) scan type.
n
MS scan mode Scan modes where 2 to 10 stages of
mass analysis are performed. The scan power equals
2 to 10, where the scan power is the power n in the
n n
expression MS . MS
for the scan mode, which can include the following:
• The scan mode corresponding to the two or more
stages of mass analysis in a two-stage full- or
narrow-scan experiment.
• The scan mode corresponding to the 3 to 10 stages
of mass analysis (n = 3 to n = 10) in a multistage
full-scan experiment.
Orbitrap Tribrid Series Getting Started Guide
Glossary: ion detection system
2+
,
is the most general expression
91