Clever Geek Handbook
📜 ⬆️ ⬇️

Isotopic composition of water

The isotopic composition of water is the percentage of molecules with different isotopic masses (isotopologues) in water. The content of water, consisting of light stable isotopes 1 H 2 16 O (“light water”, in contrast to containing an increased amount of the heavy hydrogen isotope 2 H “ heavy water ”) in natural water is 99.73 - 99.76 mol.%. [1] [2]

Content

Isotope of water

Isotopes are varieties of atoms of the same chemical element that have the same nuclear charge and the structure of electron shells that differ in the mass of the nuclei. The mass difference is due to the fact that the isotope nuclei contain the same number of protons p and different numbers of neutrons n . Combinations of various isotope atoms provide a set of isotopologic molecules.

Isotopologists are molecules that differ only in the isotopic composition of the atoms of which they are composed. An isotopologist incorporates at least one atom of a certain chemical element, which differs in number of neutrons from the rest.

A water molecule consists of two hydrogen atoms and one oxygen atom.

For the first time, the existence of hydrogen isotopes was confirmed in the publication [3] of 1932 by the American physicist-chemist G. Yuri .

Hydrogen has two stable isotopes - protium (H) - 1 H and deuterium (D) - 2 H.

Oxygen has three stable isotopes: 16 O, 17 O and 18 O (Table 1).

Table 1. Isotopes of water
ElementHydrogenOxygen
IsotopeND16 O17 o18 o
The number of protons in the nucleusoneoneeighteighteight
The number of neutrons in the nucleus0oneeight9ten
Atomic massone2sixteen1718

Combinations of 5 stable isotopes of hydrogen and oxygen give a set of 9 water isotopologous molecules (Table 2).

Table 2. Water isotopologues
Isotopologist1 H 2 16 O1 HD 16 OD 2 16 O1 H 2 17 O1 HD 17 OD 2 17 O1 H 2 18 O1 HD 18 OD 2 18 O
Hydrogen isotopes1 H1 H, DD1 H1 H, DD1 H1 H, DD
Oxygen isotopes16 O16 O16 O17 o17 o17 o18 o18 o18 o
Molecular mass18nineteen20nineteen2021202122

The 1 H 2 16 O molecule is the lightest of all water isotopologues. It is water 1 H 2 16 O that should be considered classic or light water.

Light water as a monoisotopic composition 1 H 2 16 O is the limiting case of isotopic purity. Under natural conditions, such clear, light water does not exist. To obtain the isotopologue 1 H 2 16 O, thin multi-stage purification of natural waters is carried out or synthesized from the starting elements 1 H 2 and 16 O 2 .

Natural water is a multicomponent mixture of isotopologists. The content of the lightest isotopologist in it significantly exceeds the concentration of all the others combined. In natural waters, 1,000,000 molecules contain on average 997,284 molecules of 1 H 2 16 O, 311 molecules of 1 HD 16 O, 390 molecules of 1 H 2 17 O, and about 2005 molecules of 1 H 2 18 O.

The concentration of water molecules containing heavy isotopes D, 17 O, 18 O in natural water varies within the limits fixed in the basic standards for the isotopic composition of the hydrosphere SMOW and SLAP (Table 3). Weighted amounts of isotopologists in natural water were calculated on the basis of data on the direct determination of their content by molecular spectroscopy [4] .

Table 3. The calculated weight quantities of isotopologists in natural water that meet the international standards SMOW (average molecular weight = 18.01528873) and SLAP (average molecular weight = 18.01491202), [5] .
Isotopologue of waterMolecular massContent, g / kg
SmowSLAP
1 H 2 16 O18,01056470997.032536356997,317982662
1 HD 16 O19,016841440.3280000970.187668379
D 2 16 O20,023118190.0000269000.000008804
1 H 2 17 O19,014781270.4115090700.388988825
1 HD 17 O20.021058010.0001349980.000072993
D 2 17 O21,027334760.0000000110.000000003
1 H 2 18 O20,014810372.2270637382,104884332
1 HD 18 O21.021087110,0007287690,000393984
D 2 18 O22,027363860.0000000590.000000018

As can be seen from table 3, in natural water, the weight concentration of heavy isotopologists can reach 2.97 g / kg, which is a significant value, comparable, for example, with the content of mineral salts.

Natural water, similar in content to the 1 H 2 16 O isotopologue to the SLAP standard, and also specially purified with a significantly increased proportion of this isotopologist compared to the SLAP standard, is defined as very pure light water (a less stringent definition that is applicable in real life).

In light water, the proportion of the lightest isotopologist is (mol.%):

99.76 < 1 H 2 16 O ≤ 100.

If all heavy molecules with a mass content of 2.97 g / kg are removed from water that meets the SMOW standard and replaced with 1 H 2 16 O, then the mass of 1 liter of such light and isotopically pure water will decrease by 250 mg. Thus, the parameters of light water, first of all, its “lightness” and isotopic composition can be measured using methods such as mass spectrometry , gravimetry , laser absorption spectroscopy [6] , NMR .

International standards for natural waters of various isotopic composition

The content of heavy isotopes of hydrogen and oxygen in natural waters is determined by two international standards introduced by the International Atomic Energy Agency (IAEA) [7] [8] :

  • VSMOW (Vienna Standard Mean Ocean Water) defines the isotopic composition of the deep water of the oceans.
  • SLAP (Standard Light Antarctic Precipitation) defines the isotopic composition of natural water from the Antarctic.

According to the international standard VSMOW, the absolute content of deuterium and oxygen-18 in ocean water is [9] : D VSMOW / 1 H VSMOW = (155.76 ± 0.05) ⋅ 10 −6 , or 155.76 ppm 18 O VSMOW / 16 O VSMOW = (2005.20 ± 0.45) ⋅ 10 −6 , or 2005 ppm. For the SLAP standard, the concentrations in water are [10] : deuterium D / H = 89⋅10 −6 or 89 ppm, oxygen-18 18 O / 16 O = 1894⋅10 −6 or 1894 ppm.

The light isotopologue content of 1 H 2 16 O in water, corresponding to the VSMOW isotopic composition, is 997.0325 g / kg (99.73 mol.%). The proportion of the lightest isotopologist in water, corresponding to the SLAP isotopic composition, is 997.3179 g / kg (99.76 mol.%).

The SLAP standard characterizes the lightest natural water on Earth. Water in different parts of the globe varies in its lightness.

Physical properties of water isotopologists

Isotopologists differ from each other in physical, chemical, and biological properties (Table 4).

Table 4. Change in the physical properties of water during isotopic substitution
Physical properties1 H 2 16 OD 2 16 O1 H 2 18 O
Density at 20 ° C, g / cm30.99701.10511.1106
Maximum Density Temperature, ° C3.9811.244.30
Melting point at 1 atm, ° C03.810.28
Boiling point at 1 atm, ° C100101.42100.14
Steam pressure at 100 ° C, Torr760.00721.60758.10
Viscosity at 20 ° C centipoise1.0021,2471,056

The equilibrium vapor pressure of water isotopologists varies, and is very significant. The smaller the mass of the water molecule, the higher the vapor pressure, which means that the vapor that is in equilibrium with water is always enriched with light isotopes of oxygen and hydrogen. Relatively small mass of elements, the isotope mass difference is large, therefore, they are able to strongly fractionate in natural processes: D / H → 100%, 18 O / 16 O → 12.5%. Isotopes of hydrogen and oxygen are most effectively fractionated in the processes of evaporation-condensation and crystallization of water.

The results of experimental studies indicate a difference in the physicochemical properties of light water and deionized water of natural isotopic composition [11] .

Heavy isotopologues in natural water are impurities with respect to 1 H 2 16 O, which according to some studies can be considered as structural defects [12] .

Elimination of water heterogeneity by isotopic composition leads to an increase in its homogeneity. Light water is a more uniform fluid. Heavily isotopic molecules contained in water in natural concentrations have virtually no noticeable effect on non-living systems. To the greatest extent, the effects of light water are manifested in biological objects, which are characterized by cascade reactions.

Biological properties of heavy and light water

The first inhibitory (inhibiting) seed growth properties of heavy water were discovered in 1934 by Gilbert Lewis. [13]

The cultivation of cells in heavy water dramatically accelerates the aging process and leads to the death of the culture. [14] [15]

In experiments on mammals (mice), which were fed with heavy water (3% heavy water), it was shown that negative effects increase from generation to generation, including decreased male activity and lactation in females, reduced birth weight and worsened coat condition . The third generation of animals drinking heavy water was not obtained.
On the contrary, watering animals with water with a low deuterium content caused increased sexual activity in males already in the first generation. Females experienced multiple pregnancy with a greater increase in the weight of the offspring. [14] [15]

The reaction of biosystems when exposed to water can vary depending on quantitative and qualitative changes in its isotopic composition. During the evolution of living organisms, a selection of biochemical processes took place with their tuning to only one isotope, usually light [16] . In the human body, "isotope fractionation occurs, accompanied by the removal of heavy stable isotopes of hydrogen and oxygen in water" [17] . The use of water with an increased concentration of heavy isotopes, in particular, deuterium, causes pronounced toxic effects at the body level [18] [19] . At the same time, positive biological activity of waters with a low (relatively natural) content of heavy isotopologues, in particular deuterium and oxygen 18 [20] [21], was recorded at different sites. Systematic studies conducted by the SSC RF “Institute of Biomedical Problems” of the Russian Academy of Sciences on creating a habitat for astronauts with the optimal isotopic composition of biogenic chemical elements have shown that water with a lower than the natural content of heavy isotopic molecules is a necessary component of the astronauts life support system during long flights [ 22]

As a universal environment in which all biological reactions take place, light water increases the speed of these reactions compared to water of natural isotopic composition. This effect is known as the kinetic isotope effect of the solvent [23] .

The transport properties of light water have been proven by studying the influence of heavy isotopologists in natural water on the dynamics of the removal of methylene blue dye from the olfactory system of Spur frogs [24] .

The most powerful effect of water purification from heavy isotopologists is on the energy apparatus of a living cell. The respiratory chain of mitochondria is distinguished by cascade reactions. Severe isotopologists slow down the rate of respiratory chain reactions. The reaction of generation of hydrogen peroxide by mitochondria with succinic acid as a substrate experimentally proved the general inhibitory effect of heavy water isotopologists. A decrease in their content in water to a level below natural concentrations de-inhibits and significantly accelerates the reaction studied [25] .

Light water exhibits antitumor activity, as shown in the works of scientists conducted in research centers in different countries [26] [27] [28] [29] . According to G. Shomlai, the results of clinical trials conducted in 1994-2001. in Hungary, showed that the survival rate of patients who used light water in combination with traditional methods of treatment or after them is higher than in patients using only chemo- or radiation therapy [30] .

The toxicoprotective properties of light water are confirmed by experimental studies [31] [32] , from which it follows that light water, purified from heavy isotopologists, effectively removes toxins and metabolic products from the body due to its transport properties.

The effects of light water on patients with type II diabetes mellitus were also noted. The results of an open preclinical study lasting 90 days showed that under the influence of light water, volunteers decreased elevated fasting glucose and decreased insulin resistance [33] .

There is also an opinion about the unproven existence of special biological properties of light water [34] .

The level of depression among the US population is largely correlated with the geographical distribution of deuterium, and a series of independent animal experiments have confirmed the causal relationship of depression and anhedonia with the content of deuterium in drinking water. It has been shown that replacing regular drinking water with deuterium-depleted water counteracts depression comparable to antidepressant medication results. Drinking deuterium-depleted water can be the foundation of a new strategy for preventing depression. [35] [36]

See also

  • Water
  • Heavy water
  • Hydrogen isotopes
  • Oxygen isotopes

Notes

  1. ↑ Kulsky L.A., Dal V.V., Lenchina L. Familiar and mysterious water.- Kiev: “Radyanska school”, 1982.- 120 p.
  2. ↑ Petryanov-Sokolov I.V.The most unusual substance in the world. // Chemistry and life. 2007. No 1. p.26.
  3. ↑ Harold C. Urey, FG Brickwedde, and GM Murphy. A Hydrogen Isotope of Mass 2 // Columbia University and the Bureau of Standards.
  4. ↑ Rothman et al., J. Quant. Spectrosc. Radiat. Transfer, 1998, 60, 665. Rothman et al., J. Quant. Spectrosc. Radiat. Transfer, 2003, 82, p. 9.
  5. ↑ Patent RU 2295493. “Method and installation for the production of light water”. Soloviev S.P.
  6. ↑ Lis G., Wassenaar LI, Hendry MJ High-Precision Laser Spectroscopy D / H and 18 O / 16 O Measurements of Microliter Natural Water Samples.// Anal. Chem. 2008.V. 80 (1). P. 287-293
  7. ↑ Ferronsky V.I., Polyakov V.A. Isotopy of the hydrosphere. M .: Nauka, 1983.
  8. ↑ Craig, H. Standard for Reporting Concentrations of Deuterium and Oxygen-18 in Natural Waters. // Science. 1961. V. 133. PP. 1833-1834.
  9. ↑ Hagemann R., Niff G., Roth E. Absolute isotopic scale for deuterium analysis of natural waters. Absolute D / H ratio for SMOW. // Tellus. 1970. V. 22. N6. PP.712-715.
  10. ↑ De Wit JC, van der Straaten CM; Mook WG Determination of the Absolute Hydrogen Isotopic Ratio of VSMOW and SLAP. // Geostandards Newsletter. 1980. V. 4. N. 1. PP. 33−36.
  11. ↑ VV Goncharuk, VB Lapshin, TN Burdeinaya, TV Pleteneva, AS Chernopyatko et al. Physicochemical Properties and Biological Activity of the Water Depleted of Heavy Isotopes // 2011, published in Khimiya i Tekhnologiya Vody, 2011, Vol. 33, No. 1, pp. 15-25. Journal of Water Chemistry and Technology, 2011, Vol. 33, No. 1, pp. 8-13.
  12. ↑ Smirnov A.N., Lapshin V.B., Balyshev A.V., Lebedev I.M., Goncharuk V.V., Syroeshkin A.V. Water structure: giant heterophase water clusters. // Chemistry and technology of water. - 2005.- No. 2. - C. 11-37; Smirnov A.N., Syroeshkin A.V. Supranadmolecular complexes of water. // Grew. Chem. g. - 2004.- T.48 - No. 2. - C. 125-135
  13. ↑ Lewis, GN, Biology of heavy water. Science, 79, 151 (1934)
  14. ↑ 1 2 Toroptsev I.V. et al. The biological role of heavy water in living organisms. Questions of radiobiology and hematology, Tomsk University Press, 1966
  15. ↑ 1 2 Original publication I. Toroptsev et al. The biological role of heavy water in living organisms. Questions of radiobiology and hematology, Tomsk University Press, 1966
  16. ↑ Sinyak Yu. E., Grigoriev A. I. Optimal isotopic composition of biogenic chemical elements on board manned spacecraft. // Aerospace and environmental medicine. 1996.V. 30, No. 4, S. 26.
  17. ↑ Sinyak Yu. E., Skuratov V.M., Gaidadymov V. B., Ivanova S. M., Pokrovsky B. G. Grigoriev A. I. Investigation of the fractionation of stable isotopes of hydrogen and oxygen at the international space station. // Aerospace and environmental medicine. 2005.Vol. 39, No. 6, P. 43.
  18. ↑ Denko E.I.The effect of heavy water (D2O) on animal, plant cells, and microorganisms. // Usp. modern Biol .. 1970.V. 70, No. 4, P. 41.
  19. ↑ Lobyshev V. I. Mechanisms of the thermodynamic and kinetic isotopic effects of D2O in biological systems. Doct. dissertations. Moscow, - 1987 (Biological Faculty of Moscow State University)
  20. ↑ GLEASON JD, FRIEDMAN I. Oats may grow better in water depleted in oxygen 18 and deuterium. NATURE 256, 305 (24 July 1975)
  21. ↑ Bild W, Năstasă V, Haulică I. In vivo and in vitro research on the biological effects of deuterium-depleted water: 1. Influence of deuterium-depleted water on cultured cell growth. // Rom J. Physiol. 2004. V.41. N 1-2. P: 53-67.
  22. ↑ Sinyak Y., Grigoriev A., Gaydadimov V., Gurieva T., Levinskih M., Pokrovskii B. Deuterium-free water (1H2O) in complex life-support systems of long-space space missions. // Acta Astronautica. 2003. V. 52, P. 575.
  23. ↑ Reichardt K. "Solvents and environmental effects in organic chemistry." -M .: "World", 1991. - 763 p.
  24. ↑ T. N. Burdeynaya, V. A. Poplinskaya, A. S. Chernopyatko, E. N. Grigoryan. The influence of light water on the dynamics of the removal of the dye from the olfactory system of the larvae of Xenopus laevis // Water: chemistry and ecology 2011.-No. 9 - C. 86-91
  25. ↑ Pomytkin IA, Kolesova OE // Bulletin of Experimental Biology and Medicine. 2006. V.142. N 5.
  26. ↑ Gyöngyi Z, Somlyai G. Deuterium depletion can decrease the expression of C-myc Ha-ras and p53 gene in carcinogen-treated mice. // In Vivo. 2000. V.14. N.3. P. 437.
  27. ↑ Berdea P., Cuna S., Cazacu M., Tudose M. Deuterium variation of human blood serum. // Studia Universitatis Babeş-Bolyai, Physica. 2001. Special issue
  28. ↑ Krempels K., Somlyai I., Somlyai G. A Retrospective Evaluation of the Effects of Deuterium Depleted Water Consumption on 4 Patients with Brain Metastases from Lung Cancer. // Integrative Cancer Therapies. 2008. V.7. N.3. P. 172-181.
  29. ↑ Cong F.-S., Zhang Y.-R., Sheng H.-C., Ao Z.-H., Zhang S.-Y., Wang J.-Y. Deuterium-depleted water inhibits human lung carcinoma cell growth by apoptosis. // Experimental and Therapeutic Medicine. 2010. V.1. N.2. P.277-283
  30. ↑ Somlyai G. “Let's Defeat Cancer!” Akadémiai Kiadó, Budapest, 2001.
  31. ↑ Doina PM et al., Bulletin UASVM, Veterinary Medicine. 2008. V. 65 (1). P.1843
  32. ↑ Anti-aging effects of deuterium depletion on Mn-induced toxicity in a C. elegansmodel Daiana Silva Ávilaa, c, Gábor Somlyaib, Ildikó Somlyaib, Michael Aschner
  33. ↑ Gábor Somlyai, Miklós Molnár, Ildikó Somlyai, István Fórizs, György Czuppon. Effect of subnormal level of .... - 2015-06-08.
  34. ↑ Peter Tolstoy, Elena Tupikina. Light water is a hard case // Science and Life . - 2018. - No. 8 . - S. 52-57 .
  35. ↑ Strekalova T., Evans M., Chernopiatko A. et al. Deuterium content of water increases depression susceptibility: The potential role of a serotonin-related mechanism. Behav. Brain Res. Epub 2014 Aug 1.
  36. ↑ Tatyana Strekalova, Matthew Evans, Anton Chernopyatko, et al. The deuterium content in water enhances susceptibility to depression: the potential role of the mechanism associated with serotonin, 2014.

Links

  • SMOW
  • Isotopologue (English)
  • Isotopic methods in geology - an article from the Great Soviet Encyclopedia .
Source - https://ru.wikipedia.org/w/index.php?title= Isotopic composition of the water &oldid = 98221998


More articles:

  • World War I chemical warfare agents
  • Seletskoe Lake (Karelia)
  • Ngen
  • 1900 Summer Olympics Tennis - Men's Doubles Tournament
  • Mgaloblishvili, Grigol Zurabovich
  • Octopuses
  • Iceliev, Leonid Izrailevich
  • Gordeev, Gabriel Yuryevich
  • Sociability
  • Razbezhkina, Marina Alexandrovna

All articles

Clever Geek | 2019