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About Isotopes

Isotopes are variants of chemical elements: while all isotopes of a given element contain the same number of protons, they vary in the number of neutrons they contain. Variation in neutron number produces chemically identical atoms with different masses, which can be exploited to allow tracing of specific individual atoms through a system.

Stable isotopes

Stable isotopes are generally defined as non-radioactive isotopic elements that do not decay over time. Radioactive isotopes may also be classified as stable isotopes when their half-lives are too long to be measured. These elements can often be found to occur in nature and include isotopes of carbon, nitrogen, hydrogen, oxygen, noble gases and metals. For example, three naturally occurring isotopes of hydrogen include protium (H) having one neutron, deuterium (2H) having two neutrons, and tritium having three neutrons.

Isotopically labeled compounds

Isotopically labelled compounds are compounds that incorporate isotopic elements within their molecular structure and are thus ‘labelled’ by the isotope. These compounds are used to study chemical and biochemical reactions, metabolic pathways or cellular transport. Specifically, isotope-labelled compounds are routinely used for a variety of applications including magnetic resonance imaging (MRI), spectroscopy, nuclear magnetic resonance (NMR), and geochemical analyses. An example of using an isotopic label includes replacing the most common isotope of hydrogen, protium, with deuterium to observe hydrogen exchange reactions in water.

Isotope separation methods

Distillation and Diffusion Processes

Distillation or diffusion are processes which are for enrichment used when there are relatively large mass differences between different isotopes of an element.

Centrifuge enrichment

Centrifuge processes for enrichment includes gas centrifugation and improvements upon the gas centrifuge techniques. This process involves rotating cylinders in order to move the heavier gas molecules containing a given isotope to the outer radius of the cylinder while collecting the lighter gas molecules containing the given isotope in the center of the cylinder.

Electromagnetic enrichment

Electromagnetic isotope separation processes involves first vaporizing the isotope containing molecules followed by ionizing the vapor with positively charged ions. A mass spectrometer, known as the Calutron, is then used to redirect a stream of cations onto a target for collection.

Other methods: laser enrichment, photochemical enrichment and plasma separation

Laser enrichment processes provide for lower energy inputs and thus more economical enrichment. One method currently under investigation is known as the Separation of Isotopes by Laser Excitiation (SILEX). Another laser method that is used to enrich uranium containing the 235U atom is known as molecular laser isotope separation (MLIS) which involves using infrared laser at UF6 molecules and a second laser to free a fluorine atom resulting in precipitation of the remaining UF5 compound out of the gas.

Plasma separation involves the principle of ion cyclotron resonance and uses superconducting magnets to energize a given isotope in plasma consisting of an ionic mixture.



Metabolic studies

Biochemical markers and probes are used to research the uptake of compounds by the body. For example, nutritional studies are commonly performed using isotopic labeled compounds.

Brain and kidney function

Studies of brain and kidney function are performed by tracing isotopes throughout these organs for both diagnostics and treatment applications.


Precursors for therapeutic radioisotopes or radiation therapy are used for a variety of therapies. For example, neuroendocrine tumors are treated by radiotherapy using hormone bound lutetium-177 and yttrium-90.

Clinical pharmacology

Tracing drug metabolism requires the use of isotopes bound to drug in order to understand the processing of the given pharmaceutical by the body.



A wide range of biochemical processes can be studied using stable isotopes. For example, a technique known as stable isotope labeling by amino acids in cell culture (SILAC) is used in proteomics research to help identify disease biomarkers.


The use of isotope labeling allows chemists to study the mechanisms of chemical reactions, as individual atoms can be followed through a system.

Environmental science

Isotopes are valuable for studying release and spread of pollutants in the environment.


The tracing of isotope movement, either within a local system such as an estuary or on a global scale, can allow study of circulation patterns.


Various compounds labeled with nitrogen-15 are used in the study of processes such as plant metabolism and fertilizer uptake.

Isotope Products

Isotopic metals and compounds are available in a variety of forms and enrichment levels. Compounds include stable isotopes containing carbon, nitrogen, deuterium, noble gases, and metals such as oxides, sulfates, carbonates and more. Additionally, we can produce custom syntheses according to customer needs and specifications for research and development.

American Elements manufactures a comprehensive array of materials for thin film deposition, including evaporation matterials, organometallic precursors, and sputtering targets. We offer evaporation materials such as pure metals, oxides, fluorides, alloys, and other compounds in the forms of pellets, pieces, powders, wires, rods, ingots, chunks, shot, tablets, and many others. Below is a select offering of our thin film materials catalog; for forms and materials not included in this, you may visit our Metals, Alloys, or Organometallics product catalogs; you may also request a quote directly for a material. We custom manufacture all materials to customer specifications for shape, size, purity, composition in all amounts including bulk quantities.

For the American Elements catalog of Sputtering Target products, please click here.

Health, Safety & Transportation Information

Ytterbium is considered to be fairly toxic. Safety data for Ytterbium and its compounds can vary widely depending on the form. For potential hazard information, toxicity, and road, sea and air transportation limitations, such as DOT Hazard Class, DOT Number, EU Number, NFPA Health rating and RTECS Class, please see the specific material or compound referenced in the Products tab. The below information applies to elemental (metallic) Ytterbium.

Safety Data
Material Safety Data Sheet MSDS
Signal Word Danger
Hazard Statements H228-H302-H312-H315-H319-H332-H335
Hazard Codes F,Xn
Risk Codes 11-20/21/22
Safety Precautions 16-33-36
RTECS Number ZG1925000
Transport Information UN 3089 4.1/PG 2
WGK Germany 3
Globally Harmonized System of
Classification and Labelling (GHS)
Exclamation Mark-Acute Toxicity Flame-Flammables

Recent Research & Development for Isotopes

  • Ozan Artun, Hüseyin Aytekin, Calculation of excitation functions of proton, alpha and deuteron induced reactions for production of medical radioisotopes 122–125I, Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, Volume 345, 15 February 2015
  • Joshua Blair, David S. Mebane, A Bayesian approach to electrical conductivity relaxation and isotope exchange/secondary ion mass spectrometry, Solid State Ionics, Volume 270, February 2015
  • K. Iida, M. Notani, Y. Uesugi, Y. Tanaka, T. Ishijima, Suppression of hydrogenated carbon film deposition and hydrogen isotope retention by nitrogen addition into cold remote H/D and CH4 mixture plasmas, Journal of Nuclear Materials, Available online 9 January 2015
  • Marcell Pálmai, Roland Szalay, Dorota Bartczak, Zoltán Varga, Lívia Naszályi Nagy, Christian Gollwitzer, Michael Krumrey, Heidi Goenaga-Infante, Total synthesis of isotopically enriched Si-29 silica NPs as potential spikes for isotope dilution quantification of natural silica NPs, Journal of Colloid and Interface Science, Available online 6 January 2015
  • Ross W. Stephens, Karen J. Knox, Lee A. Philip, Kelly M. Debono, Jessica L. Bell, David W. King, Christopher R. Parish, Tim J. Senden, Marcel R. Tanudji, Jillean G. Winter, Stephanie A. Bickley, Michael J. Tapner, Jian H. Pang, Stephen K. Jones, The uptake of soluble and nanoparticulate imaging isotope in model liver tumours after intra-venous and intra-arterial administration, Biomaterials, Volume 39, January 2015
  • Nicole M. Burt, Individual dietary patterns during childhood: an archaeological application of a stable isotope microsampling method for tooth dentin, Journal of Archaeological Science, Volume 53, January 2015
  • Cheng-Bang An, Weimiao Dong, Hu Li, Pingyu Zhang, Yongtao Zhao, Xueye Zhao, Shi-Yong Yu, Variability of the stable carbon isotope ratio in modern and archaeological millets: evidence from northern China, Journal of Archaeological Science, Volume 53, January 2015
  • Linda M. Reynard, Noreen Tuross, The known, the unknown and the unknowable: weaning times from archaeological bones using nitrogen isotope ratios, Journal of Archaeological Science, Volume 53, January 2015
  • J.L. Barton, Y.Q. Wang, R.P. Doerner, G.R. Tynan, Development of an analytical diffusion model for modeling hydrogen isotope exchange, Journal of Nuclear Materials, Available online 27 December 2014
  • T. Wauters, D. Douai, D. Kogut, A. Lyssoivan, S. Brezinsek, E. Belonohy, T. Blackman, V. Bobkov, K. Crombé, A. Drenik, M. Graham, E. Joffrin, E. Lerche, T. Loarer, P.L. Lomas, M.-L. Mayoral, I. Monakhov, M. Oberkofler, V. Philipps, V. Plyusnin, G. Sergienko, D. Van Eester, JET EFDA Contributors, Isotope Exchange by Ion Cyclotron Wall Conditioning on JET, Journal of Nuclear Materials, Available online 26 December 2014