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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.
An ion source is a device that creates atomic and molecular ions. Ion sources are used to form ions for mass spectrometers, optical emission spectrometers, particle accelerators, ion implanters and ion engines.
Electrospray ionization (ESI) is a technique used in mass spectrometry to produce ions using an electrospray in which a high voltage is applied to a liquid to create an aerosol. It is especially useful in producing ions from macromolecules because it overcomes the propensity of these molecules to fragment when ionized. ESI is different from other ionization processes since it may produce multiple-charged ions, effectively extending the mass range of the analyser to accommodate the kDa-MDa orders of magnitude observed in proteins and their associated polypeptide fragments.
Tandem mass spectrometry, also known as MS/MS or MS2, is a technique in instrumental analysis where two or more stages of analysis using one or more mass analyzer are performed with an additional reaction step in between these analyses to increase their abilities to analyse chemical samples. A common use of tandem MS is the analysis of biomolecules, such as proteins and peptides.
Accelerator mass spectrometry (AMS) is a form of mass spectrometry that accelerates ions to extraordinarily high kinetic energies before mass analysis. The special strength of AMS among the different methods of mass spectrometry is its ability to separate a rare isotope from an abundant neighboring mass. The method suppresses molecular isobars completely and in many cases can also separate atomic isobars. This makes possible the detection of naturally occurring, long-lived radio-isotopes such as 10Be, 36Cl, 26Al and 14C.
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.
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 and various organic molecules, 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 ways of obtaining ions of large molecules in the gas phase, though MALDI typically produces far fewer multi-charged ions.
Liquid chromatography–mass spectrometry (LC–MS) is an analytical chemistry technique that combines the physical separation capabilities of liquid chromatography with the mass analysis capabilities of mass spectrometry (MS). Coupled chromatography – MS systems are popular in chemical analysis because the individual capabilities of each technique are enhanced synergistically. While liquid chromatography separates mixtures with multiple components, mass spectrometry provides spectral information that may help to identify each separated component. MS is not only sensitive, but provides selective detection, relieving the need for complete chromatographic separation. LC–MS is also appropriate for metabolomics because of its good coverage of a wide range of chemicals. This tandem technique can be used to analyze biochemical, organic, and inorganic compounds commonly found in complex samples of environmental and biological origin. Therefore, LC–MS may be applied in a wide range of sectors including biotechnology, environment monitoring, food processing, and pharmaceutical, agrochemical, and cosmetic industries. Since the early 2000s, LC–MS has also begun to be used in clinical applications.
In analytical chemistry, ashing or ash content determination is the process of mineralization by complete combustion for preconcentration of trace substances prior to a chemical analysis, such as chromatography, or optical analysis, such as spectroscopy.
1-Naphthaleneacetic acid (NAA) is an organic compound with the formula C10H7CH2CO2H. This colorless solid is soluble in organic solvents. It features a carboxylmethyl group (CH2CO2H) linked to the "1-position" of naphthalene.
The terms glycans and polysaccharides are defined by IUPAC as synonyms meaning "compounds consisting of a large number of monosaccharides linked glycosidically". However, in practice the term glycan may also be used to refer to the carbohydrate portion of a glycoconjugate, such as a glycoprotein, glycolipid, or a proteoglycan, even if the carbohydrate is only an oligosaccharide. Glycans usually consist solely of O-glycosidic linkages of monosaccharides. For example, cellulose is a glycan composed of β-1,4-linked D-glucose, and chitin is a glycan composed of β-1,4-linked N-acetyl-D-glucosamine. Glycans can be homo- or heteropolymers of monosaccharide residues, and can be linear or branched.
Mercury(II) sulfate, commonly called mercuric sulfate, is the chemical compound HgSO4. It is an odorless salt that forms white granules or crystalline powder. In water, it separates into an insoluble basic sulfate with a yellow color and sulfuric acid.
Tyrosylprotein sulfotransferase is an enzyme that catalyzes tyrosine sulfation.
Dame Carol Vivien Robinson, is a British chemist and former president of the Royal Society of Chemistry (2018–2020). She was a Royal Society Research Professor and is the Dr Lee's Professor of Physical and Theoretical Chemistry, and a professorial fellow at Exeter College, University of Oxford. She is the founding director of the Kavli Institute for Nanoscience Discovery, University of Oxford, and she was previously professor of mass spectrometry at the chemistry department of the University of Cambridge.
Collision-induced dissociation (CID), also known as collisionally activated dissociation (CAD), is a mass spectrometry technique to induce fragmentation of selected ions in the gas phase. The selected ions are usually accelerated by applying an electrical potential to increase the ion kinetic energy and then allowed to collide with neutral molecules. In the collision, some of the kinetic energy is converted into internal energy which results in bond breakage and the fragmentation of the molecular ion into smaller fragments. These fragment ions can then be analyzed by tandem mass spectrometry.
16α-Hydroxydehydroepiandrosterone sulfate (16α-OH-DHEA-S), also known as 16α-hydroxy-17-oxoandrost-5-en-3β-yl sulfate, is an endogenous, naturally occurring steroid and a metabolic intermediate in the production of estriol from dehydroepiandrosterone (DHEA) during pregnancy. It is the C3β sulfate ester of 16α-hydroxy-DHEA.
Epietiocholanolone, also known as 3β-hydroxy-5β-androstan-17-one or as etiocholan-3β-ol-17-one, is an etiocholane (5β-androstane) steroid as well as an inactive metabolite of testosterone that is formed in the liver. The metabolic pathway is testosterone to 5β-dihydrotestosterone, 5β-dihydrotestosterone to 3β,5β-androstanediol, and 3β,5β-androstanediol to epietiocholanolone. Epietiocholanolone can also be formed directly from 5β-androstanedione. It is glucuronidated and sulfated in the liver and excreted in urine.
Jennifer S. Brodbelt is an American chemist known for her research using mass spectrometry to characterize organic compounds, especially biopolymers and proteins.
Sulfur isotope biogeochemistry is the study of the distribution of sulfur isotopes in biological and geological materials. In addition to its common isotope, 32S, sulfur has three rare stable isotopes: 34S, 36S, and 33S. The distribution of these isotopes in the environment is controlled by many biochemical and physical processes, including biological metabolisms, mineral formation processes, and atmospheric chemistry. Measuring the abundance of sulfur stable isotopes in natural materials, like bacterial cultures, minerals, or seawater, can reveal information about these processes both in the modern environment and over Earth history.
Estradiol 3-glucuronide 17β-sulfate (E2-3G-17S) is an endogenous estrogen conjugate and metabolite of estradiol. It is related to estradiol 3-sulfate and estradiol 17β-glucuronide. Estradiol 3-glucuronide 17β-sulfate has 0.0001% of the relative binding affinity of estradiol for the ERα, one of the two estrogen receptors (ERs). It shows less than one million-fold lower potency in activating the estrogen receptors relative to estradiol in vitro.
References
- ↑ Onzo, Alberto; Acquavia, Maria A.; Cataldi, Tommaso R. I.; Ligonzo, Mattia; Coviello, Donatella; Pascale, Raffaella; Martelli, Giuseppe; Bondoni, Marcella; Scrano, Laura; Bianco, Giuliana (2020-10-30). "Coceth sulfate characterization by electrospray ionization tandem mass spectrometry". Rapid Communications in Mass Spectrometry. 34 (20): e8884. doi:10.1002/rcm.8884. ISSN 1097-0231. PMID 32648966. S2CID 220473781.
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