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Deuterium (hydrogen-2, symbol 2H or D, also known as heavy hydrogen) is one of two stable isotopes of hydrogen (the other is protium, or hydrogen-1). The deuterium nucleus, called a deuteron, contains one proton and one neutron, whereas the far more common protium has no neutrons in the nucleus. Deuterium has a natural abundance in Earth's oceans of about one atom of deuterium among every 6,420 atoms of hydrogen (see heavy water). Thus deuterium accounts for about 0.0156% by number (0.0312% by mass) of all hydrogen in the oceans: 4.85×1013 tonnes of deuterium – mainly in form of HOD (or 1HO2H or 1H2HO) and only rarely in form of D2O (or 2H2O) – in 1.4×1018 tonnes of water. The abundance of deuterium changes slightly from one kind of natural water to another (see Vienna Standard Mean Ocean Water).
Heavy water is a form of water whose hydrogen atoms are all deuterium rather than the common hydrogen-1 isotope that makes up most of the hydrogen in normal water. The presence of the heavier isotope gives the water different nuclear properties, and the increase in mass gives it slightly different physical and chemical properties when compared to normal water.
Semiheavy water is the result of replacing one of the protium in light water with deuterium. It exists whenever there is water with light hydrogen (protium, 1H) and deuterium (D or 2H) in the mix. This is because hydrogen atoms (hydrogen-1 and deuterium) are rapidly exchanged between water molecules. Water containing 50% H and 50% D in its hydrogen contains about 50% HDO and 25% each of H2O and D2O, in dynamic equilibrium. In regular water, about 1 molecule in 3,200 is HDO (one hydrogen in 6,400 is D). By comparison, heavy water D2O occurs at a proportion of about 1 molecule in 41 million (i.e., one in 6,4002). This makes semiheavy water far more common than "normal" heavy water.
The Girdler sulfide (GS) process, also known as the Geib–Spevack (GS) process, is an industrial production method for filtering out of natural water the heavy water (deuterium oxide = D2O) which is used in particle research, in deuterium NMR spectroscopy, deuterated solvents for proton NMR spectroscopy, in heavy water nuclear reactors (as a coolant and moderator) and in deuterated drugs.
In physical organic chemistry, a kinetic isotope effect (KIE) is the change in the reaction rate of a chemical reaction when one of the atoms in the reactants is replaced by one of its isotopes. Formally, it is the ratio of rate constants for the reactions involving the light (kL) and the heavy (kH) isotopically substituted reactants (isotopologues):
Vienna Standard Mean Ocean Water (VSMOW) is an isotopic standard for water, that is, a particular sample of water whose proportions of different isotopes of hydrogen and oxygen are accurately known. VSMOW is distilled from ocean water and does not contain salt or other impurities. Published and distributed by the Vienna-based International Atomic Energy Agency in 1968, the standard and its essentially identical successor, VSMOW2, continue to be used as a reference material.
Hydrogen (1H) has three naturally occurring isotopes, sometimes denoted 1
H
, 2
H
, and 3
H
. 1
H
and 2
H
are stable, while 3
H
has a half-life of 12.32(2) years. Heavier isotopes also exist, all of which are synthetic and have a half-life of less than one zeptosecond (10−21 s). Of these, 5
H
is the least stable, while 7
H
is the most.
In chemistry, isotopologues are molecules that differ only in their isotopic composition. They have the same chemical formula and bonding arrangement of atoms, but at least one atom has a different number of neutrons than the parent.
Kinetic fractionation is an isotopic fractionation process that separates stable isotopes from each other by their mass during unidirectional processes. Biological processes are generally unidirectional and are very good examples of "kinetic" isotope reactions. All organisms preferentially use lighter isotopic species, because "energy costs" are lower, resulting in a significant fractionation between the substrate (heavier) and the biologically mediated product (lighter). As an example, photosynthesis preferentially takes up the light isotope of carbon 12C during assimilation of an atmospheric CO2 molecule. This kinetic isotope fractionation explains why plant material (and thus fossil fuels, which are derived from plants) is typically depleted in 13C by 25 per mil (2.5 per cent) relative to most inorganic carbon on Earth.
Proton nuclear magnetic resonance is the application of nuclear magnetic resonance in NMR spectroscopy with respect to hydrogen-1 nuclei within the molecules of a substance, in order to determine the structure of its molecules. In samples where natural hydrogen (H) is used, practically all the hydrogen consists of the isotope 1H.
In chemistry, the hydron, informally called proton, is the cationic form of atomic hydrogen, represented with the symbol H+
. The general term "hydron", endorsed by IUPAC, encompasses cations of hydrogen regardless of isotope: thus it refers collectively to protons (1H+) for the protium isotope, deuterons (2H+ or D+) for the deuterium isotope, and tritons (3H+ or T+) for the tritium isotope.
Deuterated benzene (C6D6) is an isotopologue of benzene (C6H6) in which the hydrogen atom ("H") is replaced with deuterium (heavy hydrogen) isotope ("D").
HITRAN molecular spectroscopic database is a compilation of spectroscopic parameters used to simulate and analyze the transmission and emission of light in gaseous media, with an emphasis on planetary atmospheres. The knowledge of spectroscopic parameters for transitions between energy levels in molecules is essential for interpreting and modeling the interaction of radiation (light) within different media.
Hydrogen deuteride is an isotopologue of dihydrogen composed of two isotopes of hydrogen: the majority isotope 1H (protium) and 2H (deuterium). Its proper molecular formula is 1H2H, but for simplification, it is usually written as HD.
The mass recorded by a mass spectrometer can refer to different physical quantities depending on the characteristics of the instrument and the manner in which the mass spectrum is displayed.
Water is a polar inorganic compound that is at room temperature a tasteless and odorless liquid, which is nearly colorless apart from an inherent hint of blue. It is by far the most studied chemical compound and is described as the "universal solvent" and the "solvent of life". It is the most abundant substance on the surface of Earth and the only common substance to exist as a solid, liquid, and gas on Earth's surface. It is also the third most abundant molecule in the universe.
Hydrogen isotope biogeochemistry is the scientific study of biological, geological, and chemical processes in the environment using the distribution and relative abundance of hydrogen isotopes. There are two stable isotopes of hydrogen, protium 1H and deuterium 2H, which vary in relative abundance on the order of hundreds of permil. The ratio between these two species can be considered the hydrogen isotopic fingerprint of a substance. Understanding isotopic fingerprints and the sources of fractionation that lead to variation between them can be applied to address a diverse array of questions ranging from ecology and hydrology to geochemistry and paleoclimate reconstructions. Since specialized techniques are required to measure natural hydrogen isotope abundance ratios, the field of hydrogen isotope biogeochemistry provides uniquely specialized tools to more traditional fields like ecology and geochemistry.
Position-specific isotope analysis, also called site-specific isotope analysis, is a branch of isotope analysis aimed at determining the isotopic composition of a particular atom position in a molecule. Isotopes are elemental variants with different numbers of neutrons in their nuclei, thereby having different atomic masses. Isotopes are found in varying natural abundances depending on the element; their abundances in specific compounds can vary from random distributions due to environmental conditions that act on the mass variations differently. These differences in abundances are called "fractionations," which are characterized via stable isotope analysis.
Methane clumped isotopes are methane molecules that contain two or more rare isotopes. Methane (CH4) contains two elements, carbon and hydrogen, each of which has two stable isotopes. For carbon, 98.9% are in the form of carbon-12 (12C) and 1.1% are carbon-13 (13C); while for hydrogen, 99.99% are in the form of protium (1H) and 0.01% are deuterium (2H or D). Carbon-13 (13C) and deuterium (2H or D) are rare isotopes in methane molecules. The abundance of the clumped isotopes provides information independent from the traditional carbon or hydrogen isotope composition of methane molecules.
Isotope effect is observed when molecules containing heavier isotopes of the same elements are engaged in a chemical reaction at a slower rate. Deuterium-reinforced lipids can be used for the protection of living cells by slowing the chain reaction of lipid peroxidation. The lipid bilayer of the cell and organelle membranes contain polyunsaturated fatty acids (PUFA) are key components of cell and organelle membranes. Any process that either increases oxidation of PUFAs or hinders their ability to be replaced can lead to serious disease. Correspondingly, drugs that stop the chain reaction of lipid peroxidation have preventive and therapeutic potential.
References
- ↑ Goncharuk, Vladyslav V; Kavitskaya, Alina A; Romanyukina, Iryna Yu; Loboda, Oleksandr A (17 June 2013). "Revealing water's secrets: deuterium depleted water". Chemistry Central Journal. 7 (1): 103. doi: 10.1186/1752-153X-7-103 . PMC 3703265 . PMID 23773696.
- ↑ "Isotopes of Hydrogen". Introduction to Chemistry. 26 September 2016. Archived from the original on 31 March 2020. Retrieved 13 July 2020.
- ↑ "deuterium depleted water: Topics by WorldWideScience.org". WorldWideScience. 1 January 2001. Retrieved 13 July 2020.
- ↑ Siegenthaler, U. (1979). "Stable Hydrogen and Oxygen Isotopes in the Water Cycle". In Jäger, E.; Hunziker, J.C. (eds.). Lectures in Isotope Geology. Springer Berlin Heidelberg. pp. 264–273. doi:10.1007/978-3-642-67161-6_22. ISBN 978-3-540-09158-5.
- ↑ Reference and Intercomparison Materials for Stable Isotopes of Light Elements. IAEA. 1993. pp. 1–168.
- ↑ "Reference Sheet for International Measurement Standards" (PDF). International Atomic Energy Agency (IAEA). Archived from the original (PDF) on 2020-07-29. Retrieved 2020-03-16.
- ↑ Rothman, L.S.; Rinsland, C.P.; Goldman, A.; MASSIE, S.T.; Edwards, D.P.; Flaud, J-M.; Perrin, A.; Camy-Peyret, C.; Dana, V.; Mandin, J.-Y.; Schroeder, J.; McCann, A.; Gamache, R.R.; Wattson, R.B.; Yoshino, K.; Chance, K.V.; Jucks, K.W.; Brown, L.R.; Nemtchinov, V.; Varanasi, P. (November 1998). "The HITRAN Molecular Spectroscopic Database and Hawks (HITRAN Atmospheric Workstation): 1996 Edition". Journal of Quantitative Spectroscopy and Radiative Transfer. 60 (5): 665–710. Bibcode:1998JQSRT..60..665R. doi:10.1016/S0022-4073(98)00078-8.
- ↑ Rothman, L.S.; Barbe, A.; Chris Benner, D.; Brown, L.R.; Camy-Peyret, C.; Carleer, M.R.; Chance, K.; Clerbaux, C.; Dana, V.; Devi, V.M.; Fayt, A.; Flaud, J.-M.; Gamache, R.R.; Goldman, A.; Jacquemart, D.; Jucks, K.W.; Lafferty, W.J.; Mandin, J.-Y.; Massie, S.T.; Nemtchinov, V.; Newnham, D.A.; Perrin, A.; Rinsland, C.P.; Schroeder, J.; Smith, K.M.; Smith, M.A.H.; Tang, K.; Toth, R.A.; Vander Auwera, J.; Varanasi, P.; Yoshino, K. (November 2003). "The HITRAN molecular spectroscopic database: edition of 2000 including updates through 2001". Journal of Quantitative Spectroscopy and Radiative Transfer. 82 (1–4): 5–44. Bibcode:2003JQSRT..82....5R. doi:10.1016/S0022-4073(03)00146-8.
- ↑ Pehrsson, K.; Patterson, C.; Perry, A. "The Mineral Content of US Drinking and Municipal Water" (PDF). Beltsville, MD.: USDA, Agricultural Research Service, Human Nutrition Research Center, Nutrient Data Laboratory.
- ↑ Lewis, G. N. (1934). "Biology of heavy water". Science. 79 (2052): 151–153. Bibcode:1934Sci....79..151L. doi:10.1126/science.79.2042.151. PMID 17788137. S2CID 4106325.
- ↑ Kótai, László; Lippart, József; Gács, István; Kazinczy, Béla; Vidra, László (June 1999). "Plant-Scale Method for the Preparation of Deuterium-Depleted Water". Industrial & Engineering Chemistry Research. 38 (6): 2425–2427. doi:10.1021/ie9807248.
- ↑ Stefanescu, I.; Titescu, G.; Titescu, G. M. B. Obtaining deuterium depleted potable water involves feeding purified water to isotopic distillation column in presence of packing on theoretical plates and feeding reflux flow on plate of superior stripping zone, with specific plate ratio. Patent WO2006028400-A1, 2006.
- ↑ Stefanescu, I.; Peculea, M.; Titescu, G. Process and plant for obtaining biologically active water depleted of deuterium - from natural water or water from heavy water manufacture. Patent RO112422-B1, 1998.
- ↑ Zlotopolski, V. M. Plant for producing low-deuterium water from sea water. U.S. Patent 2005/0109604A1, 2005.
- ↑ Cong, F. S. Manufacture of deuterium-depleted water for use in pharmaceuticals, involves circulating liquid raw water between cold and heat-exchange towers, and transferring heavy constituent in cold tower to liquid phase by chemical exchange. Patent CN101117210-A, 2007.
- ↑ Huang, Feng; Meng, Changgong (5 January 2011). "Method for the Production of Deuterium-Depleted Potable Water". Industrial & Engineering Chemistry Research. 50 (1): 378–381. doi:10.1021/ie101820f.
- ↑ Hall, Harriet (6 July 2020). "Deuterium Depleted Water". skepticalinquirer.org. CFI. Archived from the original on 11 July 2020. Retrieved 11 July 2020.