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Fast Atom Bombardment
Fast atom bombardment (FAB) is an ionization technique used in mass spectrometry in which a beam of high energy atoms strikes a surface to create ions. It was developed by Michael Barber at the University of Manchester in 1980. When a beam of high energy ions is used instead of atoms (as in secondary ion mass spectrometry), the method is known as liquid secondary ion mass spectrometry (LSIMS). In FAB and LSIMS, the material to be analyzed is mixed with a non-volatile chemical protection environment, called a matrix, and is bombarded under vacuum with a high energy (4000 to 10,000 electron volts) beam of atoms. The atoms are typically from an inert gas such as argon or xenon. Common matrices include glycerol, thioglycerol, 3-nitrobenzyl alcohol (3-NBA), 18-crown-6 ether, 2-nitrophenyloctyl ether, sulfolane, diethanolamine, and triethanolamine. This technique is similar to secondary ion mass spectrometry and plasma desorption mass spectrometry. Ionization mechanism FAB is a rela ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FAB Schematic
Fab or FAB may refer to: Commerce * Fab (brand), a frozen confectionery * Fab (website), an e-commerce design web site * The FAB Awards, a food and beverage award * FAB Link, a European electricity link * Flavoured alcoholic beverage or alcopop, alcoholic drinks with circa 3–7% alcohol * First Abu Dhabi Bank, an Emirati bank * Semiconductor fabrication plant, a factory that manufactures integrated circuits, etc. Culture * ''fab'' (magazine), a Canadian gay magazine * "FAB" (song), a song by JoJo featuring Remy Ma from the 2016 album ''Mad Love'' * Fernsehen aus Berlin, a German television station * Film Advisory Board, an American ratings board * Fullmetal Alchemist Brotherhood, a Japanese anime Health and medicine * Fragment antigen-binding * French–American–British classification systems for hematological disease * Frontal Assessment Battery for the evaluation of executive function Military * Benin Armed Forces (French: ') * Brazilian Air Force (Portugues ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diethanolamine
Diethanolamine, often abbreviated as DEA or DEOA, is an organic compound with the formula HN(CH2CH2OH)2. Pure diethanolamine is a white solid at room temperature, but its tendencies to absorb water and to supercool meaning that it is often encountered as a colorless, viscous liquid. Diethanolamine is polyfunctional, being a secondary amine and a diol. Like other organic amines, diethanolamine acts as a weak base. Reflecting the hydrophilic character of the secondary amine and hydroxyl groups, DEA is soluble in water. Amides prepared from DEA are often also hydrophilic. In 2013, the chemical was classified by the International Agency for Research on Cancer as "possibly carcinogenic to humans" ( Group 2B). Production The reaction of ethylene oxide with aqueous ammonia first produces ethanolamine: :C2H4O + NH3 → H2NCH2CH2OH which reacts with a second and third equivalent of ethylene oxide to give DEA and triethanolamine: :C2H4O + H2NCH2CH2OH → HN(CH2CH2OH)2 :C2H4O + H ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alpha-amino-isobutyric Acid
2-Aminoisobutyric acid (also known as α-aminoisobutyric acid, AIB, α-methylalanine, or 2-methylalanine) is the non-proteinogenic amino acid with the structural formula H2N-C(CH3)2-COOH. It is rare in nature, having been only found in meteorites, and some antibiotics of fungal origin, such as alamethicin and some lantibiotics. Synthesis In the laboratory, 2-aminoisobutyric acid may be prepared from acetone cyanohydrin, by reaction with ammonia followed by hydrolysis. Industrial scale synthesis can be achieved by the selective hydroamination of methacrylic acid. Biological activity 2-Aminoisobutyric acid is not one of the proteinogenic amino acids and is rather rare in nature (''cf.'' non-proteinogenic amino acids). It is a strong helix inducer in peptides due to Thorpe–Ingold effect of its gem-dimethyl group. Oligomers of AIB form 310 helices. Ribosomal incorporation into peptides 2-Aminoisobutyric acid is compatible with ribosomal elongation of peptide synthesis. Kat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pipecolic Acid
Pipecolic acid (piperidine-2-carboxylic acid) is an organic compound with the formula HNC5H9CO2H. It is a carboxylic acid derivative of piperidine and, as such, an amino acid, although not one encoded genetically. Like many other α-amino acids, pipecolic acid is chiral, although the S-stereoisomer is more common. It is a colorless solid. Its biosynthesis starts from lysine. CRYM, a taxon-specific protein that also binds thyroid hormones, is involved in the pipecolic acid pathway. Medicine It accumulates in pipecolic acidemia. Pipecolic acid can be associated with some forms of epilepsy. Occurrence and reactions Like most amino acids, pipecolic acid is a chelating agent. One complex is Cu(HNC5H9CO2)2(H2O)2. Pipecolic acid was identified in the Murchison meteorite. It also occurs in the leaves of the genus ''Myroxylon'', a tree from South America. See also * Bupivacaine * Efrapeptin Efrapeptins are peptides produced by fungi in the genus ''Tolypocladium'' that have antifunga ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FAB MS
Fab or FAB may refer to: Commerce * Fab (brand), a frozen confectionery * Fab (website), an e-commerce design web site * The FAB Awards, a food and beverage award * FAB Link, a European electricity link * Flavoured alcoholic beverage or alcopop, alcoholic drinks with circa 3–7% alcohol * First Abu Dhabi Bank, an Emirati bank * Semiconductor fabrication plant, a factory that manufactures integrated circuits, etc. Culture * ''fab'' (magazine), a Canadian gay magazine * "FAB" (song), a song by JoJo featuring Remy Ma from the 2016 album ''Mad Love'' * Fernsehen aus Berlin, a German television station * Film Advisory Board, an American ratings board * Fullmetal Alchemist Brotherhood, a Japanese anime Health and medicine * Fragment antigen-binding * French–American–British classification systems for hematological disease * Frontal Assessment Battery for the evaluation of executive function Military * Benin Armed Forces (French: ') * Brazilian Air Force (Portugues ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Matrix (mass Spectrometry)
In mass spectrometry, a matrix is a compound that promotes the formation of ions. Matrix compounds are used in matrix-assisted laser desorption/ionization (MALDI), matrix-assisted ionization (MAI), and fast atom bombardment (FAB). Matrix-assisted laser desorption/ionization MALDI is an ionization technique where laser energy is absorbed by a matrix to create ions from large molecules without fragmentation. The matrix, typically in excess, is mixed with the analyze molecule and deposited on a target. A table of matrix compounds, their structures, laser wavelengths typically used, and typical application is shown below. Matrix-assisted ionization Matrix-assisted ionization is an ionization method in mass spectrometry that creates ions via the creation of particles at atmospheric pressure and transfer to the vacuum of the mass analyzer. Fast atom bombardment FAB uses a high energy beam of atoms directed at a surface to create ions. FAB matrix compounds are typically liquids. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Journal Of The American Society For Mass Spectrometry
The ''Journal of the American Society for Mass Spectrometry'' is a monthly peer-reviewed scientific journal published by ACS Publications since 2020. From 2011-2019 it was published by Springer Science+Business Media and prior to that by Elsevier. It is the official publication of the American Society for Mass Spectrometry and freely available to members. The journal covers all aspects of mass spectrometry. Until 2015, Michael L. Gross (Washington University in St. Louis) was the founding editor-in-chief; he was succeeded by Joseph A. Loo (University of California, Los Angeles). The journal is abstracted and indexed in MEDLINE MEDLINE (Medical Literature Analysis and Retrieval System Online, or MEDLARS Online) is a bibliographic database of life sciences and biomedical information. It includes bibliographic information for articles from academic journals covering medic .... References External links * Delayed open access journals Mass spectrometry journals Publications e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Ionization
Chemical ionization (CI) is a soft ionization technique used in mass spectrometry. This was first introduced by Burnaby Munson and Frank H. Field in 1966. This technique is a branch of gaseous ion-molecule chemistry. Reagent gas molecules (often methane or ammonia) are ionized by electron ionization to form reagent ions, which subsequently react with analyte molecules in the gas phase to create analyte ions for analysis by mass spectrometry. Negative chemical ionization (NCI), charge-exchange chemical ionization, atmospheric-pressure chemical ionization (APCI) and atmospheric pressure photoionization (APPI) are some of the common variants of the technique. CI mass spectrometry finds general application in the identification, structure elucidation and quantitation of organic compounds as well as some utility in biochemical analysis. Samples to be analyzed must be in vapour form, or else (in the case of liquids or solids), must be vapourized before introduction into the source. P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mass Spectrometry Reviews
''Mass Spectrometry Reviews'' (usually abbreviated as ''Mass Spectrom. Rev.''), is a peer-reviewed scientific journal, published since 1982 by John Wiley & Sons. It publishes reviews in selected topics of mass spectrometry and associated scientific disciplines bimonthly. See also *Journal of Mass Spectrometry *Rapid Communications in Mass Spectrometry *John Wiley & Sons John Wiley & Sons, Inc., commonly known as Wiley (), is an American multinational publishing company founded in 1807 that focuses on academic publishing and instructional materials. The company produces books, journals, and encyclopedias, ... Mass spectrometry journals Publications established in 1987 {{biochem-journal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Matrix-assisted Laser Desorption/ionization
In mass spectrometry, matrix-assisted laser desorption/ionization (MALDI) is an ionization technique that uses a laser energy absorbing matrix to create ions from large molecules with minimal fragmentation. It has been applied to the analysis of biomolecules ( biopolymers such as DNA, proteins, peptides and carbohydrates) and various organic molecules (such as polymers, dendrimers and other macromolecules), which tend to be fragile and fragment when ionized by more conventional ionization methods. It is similar in character to electrospray ionization (ESI) in that both techniques are relatively soft (low fragmentation) ways of obtaining ions of large molecules in the gas phase, though MALDI typically produces far fewer multi-charged ions. MALDI methodology is a three-step process. First, the sample is mixed with a suitable matrix material and applied to a metal plate. Second, a pulsed laser irradiates the sample, triggering ablation and desorption of the sample and matrix materi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caesium
Caesium (IUPAC spelling) (or cesium in American English) is a chemical element with the symbol Cs and atomic number 55. It is a soft, silvery-golden alkali metal with a melting point of , which makes it one of only five elemental metals that are liquid at or near room temperature. Caesium has physical and chemical properties similar to those of rubidium and potassium. It is pyrophoric and reacts with water even at . It is the least electronegative element, with a value of 0.79 on the Pauling scale. It has only one stable isotope, caesium-133. Caesium is mined mostly from pollucite. The element has 40 known isotopes, making it, along with barium and mercury, one of the elements with the most isotopes. Caesium-137, a fission product, is extracted from waste produced by nuclear reactors. The German chemist Robert Bunsen and physicist Gustav Kirchhoff discovered caesium in 1860 by the newly developed method of flame spectroscopy. The first small-scale applications for caesium ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protonated Molecule
In chemistry, protonation (or hydronation) is the adding of a proton (or hydron, or hydrogen cation), (H+) to an atom, molecule, or ion, forming a conjugate acid. (The complementary process, when a proton is removed from a Brønsted–Lowry acid, is deprotonation.) Some examples include *The protonation of water by sulfuric acid: *:H2SO4 + H2O H3O+ + *The protonation of isobutene in the formation of a carbocation: *:(CH3)2C=CH2 + HBF4 (CH3)3C+ + *The protonation of ammonia in the formation of ammonium chloride from ammonia and hydrogen chloride: *:NH3( g) + HCl( g) → NH4Cl( s) Protonation is a fundamental chemical reaction and is a step in many stoichiometric and catalytic processes. Some ions and molecules can undergo more than one protonation and are labeled polybasic, which is true of many biological macromolecules. Protonation and deprotonation (removal of a proton) occur in most acid–base reactions; they are the core of most acid–base reaction theories. A Brøn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
