Isotopes of hydrogen

Isotopes of hydrogen

By means of the mass spectrograph he had invented, Francis William Aston in 1927 observed that the line for hydrogen corresponded to an atomic weight on the chemical scale of 1.00756. This value differed by more than the probable experimental error from the value based on the combining weights of hydrogen compounds, 1.00777. Other workers showed that the discrepancy could be removed by postulating the existence of a hydrogen isotope of mass 2 in the proportion of one atom of ²H (or D) to 4,500 atoms of ¹H. The problem interested the U.S. chemist Harold C.Urey, who from theoretical principles predicted a difference in the vapour pressures of hydrogen (H₂) and hydrogen deuteride (HD) and thus the possibility of separating these substances by distillation of liquid hydrogen. In 1931 Urey and two collaborators detected  deuterium by its atomic spectrum in the residue of a distillation of liquid hydrogen. Deuterium was first prepared in pure form by the electrolytic method of concentration: when a water solution of an electrolyte, such as sodium hydroxide, is electrolyzed, the hydrogen formed at the cathode contains a smaller fraction of deuterium than the water, and thus deuterium is concentrated in the residue. Almost pure deuterium oxide (D₂O, heavy water (deuterium labeling water)) is obtained when the solution is reduced to 0.00001 of its original volume. Deuterium can be concentrated also by the fractional distillation of water and by various chemical exchange reactions such as the following (g and 1 indicate gaseous and liquid states, respectively): H₂O(g) + HD(g) ⇌ HDO(g) + H₂(g); HDO(g) + H₂S(g) ⇌ HDS(g) + H₂O(g); NH₃(l) + HD(g) ⇌ NH₂D(l) + H₂(g).

Tritium (T) was first prepared in 1935 by bombarding deuterium (in the form of deuterophosphoric acid) with high-energy deuterons (deuterium nuclei):

Tritium is present in minute concentrations in natural water. It is formed continuously in the upper atmosphere by cosmic-ray-induced nuclear reactions. Cosmic rays, consisting mainly of high-energy protons, react with nitrogen atoms to form neutrons, which in turn react with more nitrogen atoms to form tritium:

This naturally formed tritium ends up in the form of water and reaches the surface of Earth in rain. Tritium is radioactive; it has a half-life of 12.5 years, decaying to a very soft (low energy) negative beta particle (electron; the positive beta particle is called a positron) and a helium-3 nucleus. When a sample of water is stored, it gradually loses its tritium because of radioactive decay. Thus by analyzing water for its tritium content, it is possible to elucidate details of water circulation among oceans, the atmosphere, rivers, and lakes. Tritium is made artificially in nuclear reactors by the reaction of thermal neutrons with lithium:

Corresponding compounds of the hydrogen isotopes differ slightly in their physical properties. This difference is shown by the properties of the waters, listed in the Table, and of the elements, listed in the following Table. The same is true of their chemical properties, both thermodynamic and kinetic. Both deuterium and tritium are useful as isotopic tracers for the investigation of chemical structures and of reaction mechanisms. Generally the value of a tracer arises from the fact that, although its difference in mass or its radioactivity permits its detection, it is essentially active in the same way that the ordinary atoms of the element are. For most elements, a change of one or of a few mass units is such a small percentage of the total mass that the chemical differences between isotopes are negligible. For hydrogen, however, chemical reactions involving the different isotopes proceed at measurably different rates. These kinetic-isotope effects can be utilized in detailed studies of reaction mechanisms. The rates of reactions of compounds containing deuterium or tritium are usually less than those of the corresponding compounds of ordinary hydrogen.

Physical properties of the waters

	hydrogen oxide	deuterium oxide	tritium oxide
density at 25 degrees Celsius in grams per millilitre	0.99707	1.10451	—
melting point, degrees Celsius	0	3.81	4.49
boiling point, degrees Celsius	100	101.41	—
temperature of maximum density, degrees Celsius	3.98	11.21	13.4
maximum density in grams per millilitre	1.00000	1.10589	1.21502

 

The replacement of hydrogen by deuterium in biological systems can markedly alter the delicately balanced processes. It has been established that neither plants nor animals continue to live and thrive in water containing deuterium oxide in high concentrations.

Deuterium and tritium are of interest in connection with thermonuclear (fusion) reactions. The explosion of a hydrogen bomb involves the collision and fusion of light nuclei, including deuterium and tritium. Should a method be found for controlling such fusion processes, as was done with the fission process of the earlier atomic bomb, the raw material for a practically unlimited supply of energy would be available in the deuterium content of water. Such fusion reactions are the source of solar energy.

Deuterium oxide is useful in nuclear reactors as a moderator to slow down but not appreciably capture neutrons. It has the advantage of being a liquid that absorbs neutrons only slightly

https://www.britannica.com/science/hydrogen/Isotopes-of-hydrogen#ref621366.

What Is Heavy Water(deuterium labeling water)

What Is Heavy Water(deuterium labeling water)?

You may have heard of heavy water (deuterium labeling water) and wondered how it was different from ordinary water. Here's a look at what heavy water is and some heavy water facts.

Heavy water (deuterium labeling water)is water that contains heavy hydrogen or deuterium. Deuterium differs from the hydrogen usually found in water, protium, in that each atom of deuterium contains a proton and a neutron. Heavy water may be deuterium oxide, D₂O or it may be deuterium protium oxide, DHO.

Heavy water (deuterium labeling water) occurs naturally, although it is much less common than regular water. Approximately one water molecule per twenty million water molecules is heavy water(deuterium labeling water).

So, heavy water is an isotope that has more neutrons than ordinary water. Do you expect this makes it radioactive or not? Here's how it works. 

Ref:https://www.thoughtco.com/facts-about-deuterium-607910

Does Heavy Water (deuterium labeling water)Ice Sink or Float?

While regular ice floats in water, heavy water (deuterium labeling water) ice cubes sink in regular water. Ice made from heavy water would, however, be expected to float in a glass of heavy water(deuterium labeling water).

Heavy water (deuterium labeling water)is water made using the hydrogen isotope deuterium rather than the usual isotope (protium). Deuterium has a proton and a neutron, while protium only has the proton in its atomic nucleus. This makes deuterium twice as massive as protium.

Several factors affect the behavior of heavy water ice:

1. Deuterium forms stronger  hydrogen bonds than protium, so the bonds between hydrogen and oxygen in heavy water(deuterium labeling water) molecules would be expected to impact the water heavy water molecules pack when the substance changes from a liquid to a solid.
2. Even though deuterium is more massive than protium, the size of each atom is the same, since it is the electron shell that determines it's atomic size, not the size of an atom's nucleus.
3. Each water molecule consists of an oxygen bonded to two hydrogen atoms, so there is not a huge mass difference between a heavy water (deuterium labeling water)molecule and a regular water molecule because most of the mass comes from the oxygen atom. When measured, heavy water is about 11% denser than regular water.

While scientists could make a prediction whether heavy water ice would float or sink, it required experimentation to see what would happen.

It turns out heavy water ice does sink in regular water. The likely explanation is that each heavy water molecule is slightly more massive than a regular water molecule and heavy water (deuterium labeling water)molecules may pack more closely than regular water molecules when they form ice.

Ref:https://www.thoughtco.com/facts-about-deuterium-607910

Radioactive Heavy Water(deuterium labeling water)

Radioactive Heavy Water(deuterium labeling water)?

Many people assume heavy water (deuterium labeling water)is radioactive because it uses a heavier isotope of hydrogen, is used to moderate nuclear reactions, and is used in reactors to form tritium (which is radioactive).

Pure heavy water is not radioactive. Commercial grade heavy water(deuterium labeling water), much like ordinary tap water and any other natural water, is slightly radioactive because it contains trace amounts of tritiated water. This does not present any sort of radiation risk.

Heavy water(deuterium labeling water) used as a nuclear power plant coolant contains significantly more tritium because neutron bombardment of the deuterium in heavy water sometimes forms tritium.

Is Heavy Water Dangerous To Drink?

Although heavy water isn't radioactive, it's still not a great idea to drink a large volume of it because the deuterium from the water doesn't act quite the same way as protium (normal hydrogen isotope) in biochemical reactions. You would not suffer harm from taking a sip of heavy water (deuterium labeling water)or drinking a glass of it, but if you only drank heavy water, you'd replace enough protium with deuterium to suffer negative health effects. It's estimated you would need to replace 25-50% of the regular water in your body with heavy water to be harmed. In mammals, 25% replacement causes sterility. 50% replacement would kill you. Keep in mind, much of the water in your body comes from food you eat, not just water you drink. Also, your body naturally contains small amounts of heavy water(deuterium labeling water) and every smaller amounts of tritiated water.

 Ref:https://www.thoughtco.com/facts-about-deuterium-607910

Life cycle of deuterium labeling technology

Life cycle of deuterium labeling technology by years(1964-2017) 

Ref: patent scope

top tech companies in field of deuterium labeling

top tech companies  in field of deuterium labeling

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Applicant for deuterium labeling

Top patent assignee (applicant) for deuterium labeling (heavy water)

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Heavy Water Uses

deuterium labeling(Heavy water)

Heavy water is deuterium monoxide or water in which one or more of the hydrogen atoms is a Deuterium atoms. Deuterium monoxide has the symbol D₂O or ²H₂O. It is sometimes referred to simply as deuterium oxide. Here are facts about heavy water, including its chemical and physical properties. molecular formula

deuterium labeling(Heavy water) Facts and Properties

CAS number	7789-20-0
Molecular formula	2H2O
molar mass	20.0276 g/mol
exact mass	20.023118178 g/mol
appearance	pale blue transparent liquid
odor	odorless
density	1.107 gm/cm3
melting point	3.8°C
boiling point	101.4°C
molecular weight	20.0276 g/mol
vapor pressure	16.4 mm Hg
refractive index	1.328
viscosity at 25°C	0.001095 Pa s
specific heat of fusion	0.3096 kj/g

deuterium labeling(Heavy water) Uses

• Heavy water is used as a neutron moderator in some nuclear reactors.
• Deuterium oxide is used in nuclear magnetic resonance (NMR) spectroscopy in aqueous solutions involving the study of a hydrogen nuclide.
• Deuterium oxide is used in organic chemistry to label hydrogen or to follow reactions involving water.
• Heavy water is often used instead of regular water in Fourier Transform Infrared Spectroscopy (FTIR) of proteins.
• Heavy water-moderated reactors are used to produce another isotope of hydrogen -- tritium.
• Heavy water, made using deuterium and oxygen-18, is to test human and animal metabolic rates via the doubly labeled water test.
• Heavy water has been used in a neutrino detector.

            Ref:https://www.thoughtco.com/facts-about-deuterium-607910

Deuterium Facts

Deuterium Definition

Hydrogen is unique in that it has three isotopes which are named. Deuterium is one of the isotopes of hydrogen. It has one proton and one neutron. In contrast, the most common isotope of hydrogen, protium, has one proton and  neutrons. Because deuterium contains a neutron, it is more massive or heavier than protium, so it is sometimes called heavy hydrogen.

There's a third hydrogen isotope, tritium, which may also be called heavy hydrogen because each atom contains one proton and two neutrons.

Deuterium Facts

• The chemical symbol for deuterium is D. Sometimes the symbol ²H is used.
• Deuterium is a stable isotope of hydrogen. In other words, deuterium is not radioactive.
• The natural abundance  of deuterium in the ocean is approximately 156.25 ppm, which is one atom in 6,400 of hydrogen. In other words, 99.98% of hydrogen in the ocean is protium and only 0.0156% is deuterium (or 0.0312% by mass).
• The natural abundance of deuterium is slightly different from one water source to another.
• Deuterium gas is one form of naturally occurring pure hydrogen. It's chemical formula is written as either ²H₂ or as D₂. Pure deuterium gas is rare. It's more common to find deuterium bonded to a protium atom to form hydrogen deuteride, which is written as HD or ¹H²H.
• The name for deuterium comes from the Greek word deuteros, which means "second". This is in reference two the two particles, a proton and a neutron, which make up the nucleus of a deuterium atom.

• A deuterium nucleus is termed a deuteron or deuton.
• Deuterium is used as a tracer, in nuclear fusion reactors and to slow down neutrons in heavy water moderated fission reactors.
• Deuterium was discovered in 1931 by Harold Urey. He used the new form of hydrogen to produce samples of heavy water. Urey won the Nobel Prize in 1934.

• Deuterium behaves differently from normal hydrogen in biochemical reactions. While it's not deadly to  drink a small amount of heavy water, for example, ingesting a large quantity can be lethal.
• Deuterium and tritium form stronger chemical bonds than the protium isotope of hydrogen. Of interest to pharmacology, it's harder to remove carbon from deuterium. Heavy water is more viscous than ordinary water and is 10.6 times more dense.
• Deuterium is one of only five stable nuclides that has an odd number of both protons and neutrons. In most atoms, odd numbers of protons and neutrons are unstable with respect to beta decay.
• The presence of deuterium has been confirmed on other planets in the solar system and in the spectra of stars. The outer planets have roughly the same deuterium concentration as each other. It is believed most of the deuterium present today was produced during the Big Bang nucleosynthesis event. Very little deuterium is seen in the Sun and other stars. Deuterium is consumed in stars at a faster rate than it is produced via the proton-proton reaction.
• Deuterium is made by separating naturally-occurring heavy water from a large volume of natural water. Deuterium could be produced in a nuclear reactor, but the method is not cost-effective.
• Ref:https://www.thoughtco.com/facts-about-deuterium-607910

Deuterium labeling Information

Deuterium labeling

The exchange of hydrogen with its isotope deuterium has a wide range of useful applications. The underlying principle is that while replacement of hydrogen with deuterium minimally changes the basic functions of the compound, it gives rise to clear kinetic isotope effect (KIE).

The applications include study of reaction mechanisms, isotope dilution analysis, and structural analysis of biological components. In recent years, deuterated drugs designed to slow down metabolism have been developed and tested in clinical trials. The incorporation of deuterium is also known in the field of optical and electronic devices, where it is used to enhance optical properties and durability.