Glossary - TSQ Quantis Plus MS - TSQ Fortis Plus MS - TSQ Series - TSQ Altis MS - TSQ Quantis MS - TSQ Altis Plus MS - TSQ Fortis MS - Glossary - TSQ Quantis Plus MS - TSQ Fortis Plus MS - TSQ Series - TSQ Altis MS - TSQ Altis MS - TSQ Quantis MS - TSQ Quantis MS - TSQ Altis Plus MS - TSQ Fortis MS

A tube assembly that assists in desolvating ions that are produced by the ESI, APCI, or NSI nozzle.

A DC voltage applied to the ion transfer tube. The voltage is positive for positive ions and negative for negative ions.

The sample interface between the liquid chromatograph (LC) and the mass spectrometer (MS).

Consists of the components of the API source that are held under vacuum and includes the ion spray cone, ion transfer tube, exit lens, and ion transfer tube mount.

A soft ionization technique operating at atmospheric pressure. Electrons from a corona discharge initiate the process by ionizing the mobile phase vapor molecules, forming a reagent gas. Charged species are generated in the gas phase.

Ionization performed at atmospheric pressure by using atmospheric pressure chemical ionization (APCI), heated-electrospray (H-ESI), or nanospray ionization (NSI).

A soft ionization technique that shows an ion generated from a molecule when it interacts with a photon from a light source.

The outer-coaxial gas (nitrogen) that assists the evaporation of the sample solution as it exits the ESI, APCI (optional), or APPI (optional) spray insert. The mass spectrometer heats this gas to the user-specified vaporizer temperature.

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.

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.

The energy used when ions collide with the collision gas.

A neutral gas used in the collision cell to undergo collisions with ions.

A method of fragmentation where ions are accelerated to highkinetic 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.

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.

A highly polished metal surface that converts ions from the mass analyzer into secondary electrons, which enter the electron multiplier.

A valve on the mass spectrometer that can be plumbed as a divert valve or as a loop injector.

A device used for current amplification through the secondary emission of electrons. Electron multipliers can have a discrete dynode or a continuous dynode.

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.

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.

The pump that evacuates the foreline. A rotary-vane pump is a type of forepump. It might also be referred to as a backing, mechanical, rotaryvane, roughing, or vacuum pump.

A charged dissociation product of an ionic fragmentation. Such an ion can dissociate further to form other charged molecular or atomic species of successively lower formula weights.

Provides a full mass spectrum as opposed to the selected ion monitoring (SIM) scan type, which produces only one mass. With the fullscan type, the mass analyzer is scanned from the first mass to the last mass without interruption. Also known as single-stage full-scan type.

Converts ions in solution into ions in the gas phase by using electrospray (ESI) in combination with heated auxiliary gas.

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 one ±12 kVdc conversion dynode and a discrete dynode electron multiplier.

A step in the quadrupole Q1 mass analysis where the mass analyzer ejects all ions except for the ions of interest.

Focuses and transmits ions from the API source to the mass analyzer.

The mass spectrometer can operate in either of two ion polarity modes: positive or negative.

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.

A metal disk with a circular hole in the center that allows the ion beam to pass.

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.

A device that determines the mass-tocharge ratios (m/z) of ions by one of a variety of techniques.

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. The automated calibration process tunes these values for positive and negative ions.

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.

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.

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 C7H72+, m/z = 45.5.

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.

A symmetrical, parallel array of (usually) four, six, or eight 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.

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.

The amplitude of the RF voltage applied to the multipoles.

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).

The mass of the neutral species that is lost by the precursor ion in a neutral loss experiment.

A scan mode that links together Q1 and Q3 scans 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 Q3 scan is a selected number of mass units lower than the Q1 scan.

The minimum number of intensity counts per sampling interval that is required before a signal is recorded.

The distance across a peak measured at a selected peak-height level, in minutes or mass units. The peak-height level is usually specified as a percentage of the maximum peak height.

The full width of a peak at half its maximum height, sometimes abbreviated FWHM.

An electrically charged molecular species that can dissociate to form fragments. The fragments can be electrically charged or neutral species. A precursor ion can be a molecular ion or an electrically charged fragment of a molecular ion.

The mass-to-charge ratio of a precursor ion. The location of the center of a target precursor-ion peak in mass-to-charge ratio (m/z) units.

An electrically charged fragment of an isolated precursor ion.

The mass-to-charge ratio of a product ion. The location of the center of a target production peak in mass-to-charge ratio (m/z) units.

Data representing mass spectral peaks as point-to-point plots, with each point having an associated intensity value.

Chemical analysis designed to determine the identity of the components of a substance.

Chemical analysis designed to determine the quantity or concentration of a specific substance in a sample.

A measure of the dispersion of a group of measurements relative to the mean of the group. Related standard deviation is expressed as a percentage of the average value. The percent standard deviation is calculated as: %RSD = 100 × (S / X) where S is the standard deviation and X is the sample mean.

The time after injection at which a compound elutes from a chromatographic column. The total time that the compound is retained on the chromatograph column.

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.

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, storage, or both. 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.

A scan type where the mass spectrometer acquires and records ion current following the isolation of a list of singular mass-to-charge ratio values.

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.

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.

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.

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.

A device that delivers a solution from a syringe at a specified rate.

A vacuum pump that provides a high vacuum for the mass spectrometer and detector system.

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.

Components associated with lowering the pressure within the mass spectrometer. A vacuum system includes the vacuum manifold, pumps, pressure gauges, and associated electronics.