Thermo Scientific TSQ Altis, Руководство по оборудованию

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G
150 TSQ Altis, Quantis, and Fortis Hardware Manual Thermo Scientific
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 measures and
analyses 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.
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
2+
, 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.
multipole A symmetrical, parallel array of (usually) four, six, or eight cylindrical rods that
acts as an ion transmission device. An RF voltage and DC offset voltage are applied to the
rods to create an electrostatic field that efficiently transmits ions along the axis of the
multipole rods.
multipole DC offset voltage A DC voltage applied to a multipole rod assembly. The
multipole DC offset voltage helps to define the translational kinetic energy of the ions
within the assembly.
multipole RF voltage The amplitude of the RF voltage applied to the multipoles.
N
nanoelectrospray ionization (nanoESI or NSI) A type of electrospray (ESI) that
accommodates very low flow rates of sample and solvent at 1–20 nL/min (for static
nanoelectrospray) or 100–1000 nL/min (for dynamic nanoelectrospray, which is also called
nanoESI nanoLC gradient separation).
neutral loss mass The mass of the neutral species that is lost by the precursor ion in a neutral
loss experiment.
neutral loss scan mode A scan mode that links together an MS and MS/MS scan so that
they are scanned at the same rate over scan ranges of the same width. However, the
respective mass ranges are offset by a selected mass so that the MS/MS scan is a selected
number of mass units lower than the MS scan.