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Hybrid Mass Spectrometer
A hybrid mass spectrometer is a device for tandem mass spectrometry that consists of a combination of two or more '' m/z'' separation devices of different types. Notation The different ''m/z'' separation elements of a hybrid mass spectrometer can be represented by a shorthand notation. The symbol ''Q'' represents a quadrupole mass analyzer, ''q'' is a radio frequency collision quadrupole, ''TOF'' is a time-of-flight mass spectrometer, ''B'' is a magnetic sector and ''E'' is an electric sector. Sector quadrupole A sector instrument can be combined with a collision quadrupole and quadrupole mass analyzer to form a hybrid instrument. A BEqQ configuration with a magnetic sector (B), electric sector (E), collision quadrupole (q) and ''m/z'' selection quadrupole (Q) have been constructed and an instrument with two electric sectors (BEEQ) has been described. Quadrupole time-of-flight A triple quadrupole mass spectrometer with the final quadrupole replaced by a time-of-flight device i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tandem Mass Spectrometry
Tandem mass spectrometry, also known as MS/MS or MS2, is a technique in instrumental analysis where two or more mass analyzers are coupled together using an additional reaction step to increase their abilities to analyse chemical samples. A common use of tandem MS is the analysis of biomolecules, such as proteins and peptides. The molecules of a given sample are ionized and the first spectrometer (designated MS1) separates these ions by their mass-to-charge ratio (often given as m/z or m/Q). Ions of a particular m/z-ratio coming from MS1 are selected and then made to split into smaller fragment ions, e.g. by collision-induced dissociation, ion-molecule reaction, or photodissociation. These fragments are then introduced into the second mass spectrometer (MS2), which in turn separates the fragments by their m/z-ratio and detects them. The fragmentation step makes it possible to identify and separate ions that have very similar m/z-ratios in regular mass spectrometers. Struc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
QTOF Schematic
A hybrid mass spectrometer is a device for tandem mass spectrometry that consists of a combination of two or more '' m/z'' separation devices of different types. Notation The different ''m/z'' separation elements of a hybrid mass spectrometer can be represented by a shorthand notation. The symbol ''Q'' represents a quadrupole mass analyzer, ''q'' is a radio frequency collision quadrupole, ''TOF'' is a time-of-flight mass spectrometer, ''B'' is a magnetic sector and ''E'' is an electric sector. Sector quadrupole A sector instrument can be combined with a collision quadrupole and quadrupole mass analyzer to form a hybrid instrument. A BEqQ configuration with a magnetic sector (B), electric sector (E), collision quadrupole (q) and ''m/z'' selection quadrupole (Q) have been constructed and an instrument with two electric sectors (BEEQ) has been described. Quadrupole time-of-flight A triple quadrupole mass spectrometer with the final quadrupole replaced by a time-of-flight device i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mass Spectrometer
Mass spectrometry (MS) is an analytical technique that is used to measure the mass-to-charge ratio of ions. The results are presented as a ''mass spectrum'', a plot of intensity as a function of the mass-to-charge ratio. Mass spectrometry is used in many different fields and is applied to pure samples as well as complex mixtures. A mass spectrum is a type of plot of the ion signal as a function of the mass-to-charge ratio. These spectra are used to determine the elemental or isotopic signature of a sample, the masses of particles and of molecules, and to elucidate the chemical identity or structure of molecules and other chemical compounds. In a typical MS procedure, a sample, which may be solid, liquid, or gaseous, is ionized, for example by bombarding it with a beam of electrons. This may cause some of the sample's molecules to break up into positively charged fragments or simply become positively charged without fragmenting. These ions (fragments) are then separated according ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quadrupole Mass Analyzer
The quadrupole mass analyzer, originally conceived by Nobel Laureate Wolfgang Paul and his student Helmut Steinwedel, also known as quadrupole mass filter, is one type of mass analyzer used in mass spectrometry. As the name implies, it consists of four cylindrical rods, set parallel to each other. In a quadrupole mass spectrometer (QMS) the quadrupole is the ''mass analyzer'' - the component of the instrument responsible for selecting sample ions based on their mass-to-charge ratio (''m/z''). Ions are separated in a quadrupole based on the stability of their trajectories in the oscillating electric fields that are applied to the rods. Principle of operation The quadrupole consists of four parallel metal rods. Each opposing rod pair is connected together electrically, and a radio frequency (RF) voltage with a DC offset voltage is applied between one pair of rods and the other. Ions travel down the quadrupole between the rods. Only ions of a certain mass-to-charge ratio will reach t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Frequency
Radio frequency (RF) is the oscillation rate of an alternating electric current or voltage or of a magnetic, electric or electromagnetic field or mechanical system in the frequency range from around to around . This is roughly between the upper limit of audio frequencies and the lower limit of infrared frequencies; these are the frequencies at which energy from an oscillating current can radiate off a conductor into space as radio waves. Different sources specify different upper and lower bounds for the frequency range. Electric current Electric currents that oscillate at radio frequencies (RF currents) have special properties not shared by direct current or lower audio frequency alternating current, such as the 50 or 60 Hz current used in electrical power distribution. * Energy from RF currents in conductors can radiate into space as electromagnetic waves ( radio waves). This is the basis of radio technology. * RF current does not penetrate deeply into electrical c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Time-of-flight Mass Spectrometer
Time-of-flight mass spectrometry (TOFMS) is a method of mass spectrometry in which an ion's mass-to-charge ratio is determined by a time of flight measurement. Ions are accelerated by an electric field of known strength. This acceleration results in an ion having the same kinetic energy as any other ion that has the same charge. The velocity of the ion depends on the mass-to-charge ratio (heavier ions of the same charge reach lower speeds, although ions with higher charge will also increase in velocity). The time that it subsequently takes for the ion to reach a detector at a known distance is measured. This time will depend on the velocity of the ion, and therefore is a measure of its mass-to-charge ratio. From this ratio and known experimental parameters, one can identify the ion. Theory The potential energy of a charged particle in an electric field is related to the charge of the particle and to the strength of the electric field: where ''E''p is potential energy, ''q ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sector Mass Spectrometer
A sector instrument is a general term for a class of mass spectrometer that uses a static electric (E) or magnetic (B) sector or some combination of the two (separately in space) as a mass analyzer. Popular combinations of these sectors have been the EB, BE (of so-called reverse geometry), three-sector BEB and four-sector EBEB (electric-magnetic-electric-magnetic) instruments. Most modern sector instruments are double-focusing instruments (first developed by Francis William Aston, Arthur Jeffrey Dempster, Kenneth Bainbridge and Josef Mattauch in 1936) in that they focus the ion beams both in direction and velocity. Theory The behavior of ions in a homogeneous, linear, static electric or magnetic field (separately) as is found in a sector instrument is simple. The physics are described by a single equation called the Lorentz force law. This equation is the fundamental equation of all mass spectrometric techniques and applies in non-linear, non-homogeneous cases too and is an impo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sector Instrument
A sector instrument is a general term for a class of mass spectrometer that uses a static electric (E) or magnetic (B) sector or some combination of the two (separately in space) as a mass analyzer. Popular combinations of these sectors have been the EB, BE (of so-called reverse geometry), three-sector BEB and four-sector EBEB (electric-magnetic-electric-magnetic) instruments. Most modern sector instruments are double-focusing instruments (first developed by Francis William Aston, Arthur Jeffrey Dempster, Kenneth Bainbridge and Josef Mattauch in 1936) in that they focus the ion beams both in direction and velocity. Theory The behavior of ions in a homogeneous, linear, static electric or magnetic field (separately) as is found in a sector instrument is simple. The physics are described by a single equation called the Lorentz force law. This equation is the fundamental equation of all mass spectrometric techniques and applies in non-linear, non-homogeneous cases too and is an impor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Q-TOF
A hybrid mass spectrometer is a device for tandem mass spectrometry that consists of a combination of two or more ''m/z'' separation devices of different types. Notation The different ''m/z'' separation elements of a hybrid mass spectrometer can be represented by a shorthand notation. The symbol ''Q'' represents a quadrupole mass analyzer, ''q'' is a radio frequency collision quadrupole, ''TOF'' is a time-of-flight mass spectrometer, ''B'' is a magnetic sector mass spectrometer, sector and ''E'' is an electric sector. Sector quadrupole A sector instrument can be combined with a collision quadrupole and quadrupole mass analyzer to form a hybrid instrument. A BEqQ configuration with a magnetic sector (B), electric sector (E), collision quadrupole (q) and ''m/z'' selection quadrupole (Q) have been constructed and an instrument with two electric sectors (BEEQ) has been described. Quadrupole time-of-flight A triple quadrupole mass spectrometer with the final quadrupole replaced by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triple Quadrupole Mass Spectrometer
A triple quadrupole mass spectrometer (TQMS), is a tandem mass spectrometer consisting of two quadrupole mass analyzers in series, with a (non-mass-resolving) radio frequency (RF)–only quadrupole between them to act as a cell for collision-induced dissociation. This configuration is often abbreviated QqQ, here Q1q2Q3. History The arrangement of three quadrupoles was first developed by J.D. Morrison of La Trobe University, Australia for the purpose of studying the photodissociation of gas-phase ions. After coming into contact with Prof. Christie G. Enke and his then graduate student Richard Yost, Morrison's linear arrangement of the three quadrupoles probed the construction of the first triple-quadrupole mass spectrometer. In the years following, the first commercial triple-quadrupole mass spectrometer was developed at Michigan State University by Enke and Yost in the late 1970s. It was later found that the triple-quadrupole mass spectrometer could be utilized to study organic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quadrupole Ion Trap
A quadrupole ion trap or paul trap is a type of ion trap that uses dynamic electric fields to trap charged particles. They are also called radio frequency (RF) traps or Paul traps in honor of Wolfgang Paul, who invented the device and shared the Nobel Prize in Physics in 1989 for this work. It is used as a component of a mass spectrometer or a trapped ion quantum computer. Overview A charged particle, such as an atomic or molecular ion, feels a force from an electric field. It is not possible to create a static configuration of electric fields that traps the charged particle in all three directions (this restriction is known as Earnshaw's theorem). It is possible, however, to create an ''average'' confining force in all three directions by use of electric fields that change in time. To do so, the confining and anti-confining directions are switched at a rate faster than it takes the particle to escape the trap. The traps are also called "radio frequency" traps because the switc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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