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Tandem mass spectrometry, also known as MS/MS or MS2, is a technique in instrumental analysis where two or more mass spectrometry, mass analyzers are coupled together using an additional reaction step to increase their abilities to Analytical chemistry, 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 Ionization, 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 Fragmentation (mass spectrometry), fragment ions, e.g. by collision-induced dissociation, Gas-phase ion chemistry, 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 Mass spectrometry#Detectors, detects them. The fragm ... [...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] |
MS MS
MS, ms, Ms, M.S., etc. may refer to: Arts and entertainment * ''Ms.'' (magazine), an American feminist magazine * Metal Storm (webzine), a heavy metal website based in Estonia Businesses and organizations * MS-13, criminal gang * Missionaries of La Salette, a Catholic male religious order * Młodzi Socjaliści (Young Socialists), a former Polish socialist youth organization * Morgan Stanley, a US investment bank (NYSE stock symbol: MS) * Mjólkursamsalan, an Icelandic dairy company Educational qualifications * Master of Science, a master's degree in the field of science * Master of Surgery, an advanced medical degree * Master Sommelier, a terminal degree in the field of wine * '' Mastère spécialisé'', a French postgraduate ''grande école'' master's degree Medicine * Mitral stenosis, narrowing of the mitral valve of the heart * Morphine sulfate, an opiate pain-relieving drug * Multiple sclerosis, a disease of the nervous system Military * Master seaman, a non-commissioned ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Internal Energy
The internal energy of a thermodynamic system is the total energy contained within it. It is the energy necessary to create or prepare the system in its given internal state, and includes the contributions of potential energy and internal kinetic energy. It keeps account of the gains and losses of energy of the system that are due to changes in its internal state. It does not include the kinetic energy of motion of the system as a whole, or any external energies from surrounding force fields. The internal energy of an isolated system is constant, which is expressed as the law of conservation of energy, a foundation of the first law of thermodynamics. The internal energy is an extensive property. The internal energy cannot be measured directly and knowledge of all its components is rarely interesting, such as the static rest mass energy of its constituent matter. Thermodynamics is chiefly concerned only with ''changes'' in the internal energy, not with its absolute value. Instea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ionization
Ionization, or Ionisation is the process by which an atom or a molecule acquires a negative or positive charge by gaining or losing electrons, often in conjunction with other chemical changes. The resulting electrically charged atom or molecule is called an ion. Ionization can result from the loss of an electron after collisions with subatomic particles, collisions with other atoms, molecules and ions, or through the interaction with electromagnetic radiation. Heterolytic bond cleavage and heterolytic substitution reactions can result in the formation of ion pairs. Ionization can occur through radioactive decay by the internal conversion process, in which an excited nucleus transfers its energy to one of the inner-shell electrons causing it to be ejected. Uses Everyday examples of gas ionization are such as within a fluorescent lamp or other electrical discharge lamps. It is also used in radiation detectors such as the Geiger-Müller counter or the ionization chamber. The ionizati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ion Trap
An ion trap is a combination of electric and/or magnetic fields used to capture charged particles — known as ions — often in a system isolated from an external environment. Atomic and molecular ion traps have a number of applications in physics and chemistry such as precision mass spectrometry, improved atomic frequency standards, and quantum computing. In comparison to neutral atom traps, ion traps have deeper trapping potentials (up to several electronvolts) that do not depend on the internal electronic structure of a trapped ion. This makes ion traps more suitable for the study of light interactions with single atomic systems. The two most popular types of ion traps are the Penning trap, which forms a potential via a combination of static electric and magnetic fields, and the Paul trap which forms a potential via a combination of static and oscillating electric fields. Penning traps can be used for precise magnetic measurements in spectroscopy. Studies of quantum state man ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fourier Transform Ion Cyclotron Resonance
Fourier-transform ion cyclotron resonance mass spectrometry is a type of mass analyzer (or mass spectrometer) for determining the mass-to-charge ratio (''m''/''z'') of ions based on the cyclotron frequency of the ions in a fixed magnetic field. The ions are trapped in a Penning trap (a magnetic field with electric trapping plates), where they are excited (at their resonant cyclotron frequencies) to a larger cyclotron radius by an oscillating electric field orthogonal to the magnetic field. After the excitation field is removed, the ions are rotating at their cyclotron frequency in phase (as a "packet" of ions). These ions induce a charge (detected as an image current) on a pair of electrodes as the packets of ions pass close to them. The resulting signal is called a free induction decay (FID), transient or interferogram that consists of a superposition of sine waves. The useful signal is extracted from this data by performing a Fourier transform to give a mass spectrum. History FT- ... [...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] |
