Selenium information, including Technical Data, Safety Data and its high purity properties, research, applications and other useful facts are discussed below. Scientific facts such as the atomic structure, ionization energy, abundance on Earth, conductivity and thermal properties are included.
 Selenium exhibits both photovoltaic action, where light is converted directly into electricity, and photoconductive action, where the electrical resistance decreases with increased illumination. These properties make selenium useful in the production of photocells and exposure meters for photographic use, as well as solar cells. Below its melting point, selenium is a p-type semiconductor and has many uses in electronic and solid-state applications. Selenium is available as metal and compounds with purities from 99% to 99.9999% (ACS grade to ultra-high purity); metals in the form of foil, sputtering target, and rod, and compounds as submicron and nanopowder.
Selenium facts, including appearance, CAS #, and molecular formula and safety data, research and properties are
available for many specific states, forms and shapes on the product pages listed to the left. Elemental or metallic forms include pellets, rod, wire and granules for evaporation source material purposes. Nanoparticles and nanopowders provide ultra high surface area which nanotechnology research and recent experiments demonstrate function to create new and unique properties and benefits.
Oxides are available in forms including powders and dense pellets for such uses as  optical coating and thin film applications. Oxides tend to be insoluble. Fluorides are another insoluble form for uses in which oxygen is undesirable such as metallurgy, chemical and physical vapor deposition and in some optical coatings. Selenium is available in soluble forms including chlorides, nitrates and acetates. These compounds are also manufactured as solutions at specified stoichiometries.
Selenium is a Block P, Group 16, Period 4 element. The number of electrons in each of Selenium's shells is 2, 8, 18, 6 and its electronic configuration is [Ar] 3d10 4s2 4p4. In its elemental form selenium's CAS number is 7782-49-2. The selenium atom has a radius of 116.pm and it's Van der Waals radius is 190.pm.
 All elemental metals, compounds and solutions may be synthesized in ultra high purity (e.g. 99.999%) for laboratory standards, advanced electronic, thin fillm deposition using sputtering targets and evaporation materials, metallurgy and optical materials and other high technology applications. Information is provided for stable (non-radioactive) isotopes. Organo-Metallic Selenium compounds are soluble in organic or non-aqueous solvents. See Analytical Services for information on available certified chemical and physical analysis techniques including MS-ICP, X-Ray Diffraction, PSD and Surface Area (BET) analysis.
Selenium was first discovered by Jons Berzelius in 1817. The origin of the name Selenium comes from the Greek word "Selênê" meaning moon.
 Sélénium |
 Selen |
 Selenio |
 Selênio |
 Selenio |
 Selen |
Abundance. The following table shows the abundance of selenium and each of its naturally occurring isotopes on Earth along with the atomic mass for each isotope.
| Isotope |
Atomic Mass |
% Abundance on Earth |
| Se-74 |
73.922477 |
0.89 |
| Se-76 |
75.919214 |
9.36 |
| Se-77 |
76.919915 |
7.63 |
| Se-78 |
77.917310 |
23.78 |
| Se-80 |
79.916522 |
49.61 |
| Se-82 |
81.916700 |
8.73 |
The following table shows the abundance of Selenium present in the human body and in the universe scaled to parts per billion (ppb) by weight and by atom:
| |
Typical Human Body |
Universe |
| by Weight |
no data |
0.1 ppb |
| by Atom |
no data |
0.001 ppb |
Safety Data and Biological Role. The safety data for selenium metal, nanoparticles 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 left margin. Selenium compounds, in small amounts, have an essential biological role. Selenium may help to protect against free radical oxidants and some heavy metals, it is also said to stimulate the metabolism. Sheep grown in areas with deficient amounts of Selenium in the soil can develop "white muscle disease".
Ionization Energy. The ionization energy for selenium (the least required energy to release a single electron from the atom in it's ground state in the gas phase) is stated in the following table:
| 1st Ionization Energy |
940.97 kJ mol-1 |
| 2nd Ionization Energy |
2044.54 kJ mol-1 |
| 3rd Ionization Energy |
2973.74 kJ mol-1 |
Conductivity. As to selenium's electrical and thermal conductivity, the electrical conductivity measured as to electrical resistivity @ 20 ºC is 12 μΩcm and its electronegativities (or its ability to draw electrons relative to other elements) is 2.55. The thermal conductivity of selenium is 2.04 W m-1 K-1.
Thermal Properties. The melting point and boiling point for selenium are stated below. The following chart sets forth the heat of fusion, heat of vaporization and heat of atomization.
| Heat of Fusion |
5.1 kJ mol-1 |
| Heat of Vaporization |
90 kJ mol-1 |
| Heat of Atomization |
226.4 kJ mol-1 |
Recent Research & Development for Selenium
Selenoprotein K binds multi-protein complexes and is involved in the regulation of ER homeostasis.
Shchedrina VA, Everley RA, Zhang Y, Gygi SP, Hatfield DL, Gladyshev VN.
J Biol Chem. 2011 Oct 20. [Epub ahead of print]
PMID:
22016385
[PubMed - as supplied by publisher]
Catalytic activity of selenomethionine in removing amino acid, peptide, and protein hydroperoxides.
Suryo Rahmanto A, Davies MJ.
Free Radic Biol Med. 2011 Oct 1. [Epub ahead of print]
PMID:
22015433
[PubMed - as supplied by publisher]
Combination of chemometrically assisted voltammetry, calorimetry, and circular dichroism as a new method for the study of bioinorganic substances: application to selenocystine metal complexes.
Gusmão R, Prohens R, Díaz-Cruz JM, Ariño C, Esteban M.
J Biol Inorg Chem. 2011 Oct 21. [Epub ahead of print]
PMID:
22015398
[PubMed - as supplied by publisher]
Marine and farmed fish on the Polish market: Comparison of the nutritive value and human exposure to PCDD/Fs and other contaminants.
Szlinder-Richert J, Usydus Z, Malesa-Ciecwierz M, Polak-Juszczak L, Ruczynska W.
Chemosphere. 2011 Oct 17. [Epub ahead of print]
PMID:
22014661
[PubMed - as supplied by publisher]
Dietary selenium reduces retention of methyl mercury in freshwater fish.
Bjerregaard P, Fjordside S, Hansen MG, Petrova MB.
Environ Sci Technol. 2011 Oct 20. [Epub ahead of print]
PMID:
22014184
[PubMed - as supplied by publisher]
Plant and fungal food components with potential activity on the development of microbial oral diseases.
Daglia M, Papetti A, Mascherpa D, Grisoli P, Giusto G, Lingström P, Pratten J, Signoretto C, Spratt DA, Wilson M, Zaura E, Gazzani G.
J Biomed Biotechnol. 2011;2011:274578. Epub 2011 Oct 17.
PMID:
22013381
[PubMed - in process]
Selenium, selenoproteins and the thyroid gland: interactions in health and disease.
Schomburg L.
Nat Rev Endocrinol. 2011 Oct 18. doi: 10.1038/nrendo.2011.174. [Epub ahead of print]
PMID:
22009156
[PubMed - as supplied by publisher]
Selenium inhibits migration of murine melanoma cells via down-modulation of IL-18 expression.
Song H, Kim J, Lee HK, Park HJ, Nam J, Park GB, Kim YS, Cho D, Hur DY.
Int Immunopharmacol. 2011 Oct 15. [Epub ahead of print]
PMID:
22008306
[PubMed - as supplied by publisher]
Detection, Identification, and Quantification of Selenoproteins in a Candidate Human Plasma Standard Reference Material.
Ballihaut G, Kilpatrick LE, Davis WC.
Anal Chem. 2011 Oct 18. [Epub ahead of print]
PMID:
22007999
[PubMed - as supplied by publisher]
Severe pre-eclampsia is associated with abnormal trace elements concentrations in maternal and fetal blood.
Katz O, Paz-Tal O, Lazer T, Aricha-Tamir B, Mazor M, Wiznitzer A, Sheiner E.
J Matern Fetal Neonatal Med. 2011 Oct 18. [Epub ahead of print]
PMID:
22007865
[PubMed - as supplied by publisher]
Effects of Selenium Supplements on Cancer Prevention: Meta-analysis of Randomized Controlled Trials.
Lee EH, Myung SK, Jeon YJ, Kim Y, Chang YJ, Ju W, Seo HG, Huh BY.
Nutr Cancer. 2011 Oct 17. [Epub ahead of print]
PMID:
22004275
[PubMed - as supplied by publisher]
Study of the correlation of serum selenium level with Behcet's disease.
Esalatmanesh K, Jamshidi A, Shahram F, Davatchi F, Masoud SA, Soleimani Z, Salesi M, Ghaffarpasand I.
Int J Rheum Dis. 2011 Oct;14(4):375-8. doi: 10.1111/j.1756-185X.2011.01649.x. Epub 2011 Sep 5.
PMID:
22004235
[PubMed - in process]
Multi-metal(loid) methylation in methanoarchaea is linked to central intermediates of methanogenesis.
Thomas F, Diaz-Bone RA, Wuerfel O, Huber B, Weidenbach K, Schmitz RA, Hensel R.
Appl Environ Microbiol. 2011 Oct 14. [Epub ahead of print]
PMID:
22003009
[PubMed - as supplied by publisher]
The Effects of Di(2-Ethylhexyl)Phthalate Exposure and Selenium Nutrition on Sertoli Cell Vimentin Structure and Germ-Cell Apoptosis in Rat Testis.
Erkekoglu P, Zeybek ND, Giray B, Asan E, Hincal F.
Arch Environ Contam Toxicol. 2011 Oct 16. [Epub ahead of print]
PMID:
22002783
[PubMed - as supplied by publisher]
A superoxide anion-scavenger, 1,3-selenazolidin-4-one suppresses serum deprivation-induced apoptosis in PC12 cells by activating MAP kinase.
Nishina A, Kimura H, Kozawa K, Sommen G, Nakamura T, Heimgartner H, Koketsu M, Furukawa S.
Toxicol Appl Pharmacol. 2011 Oct 2. [Epub ahead of print]
PMID:
22001386
[PubMed - as supplied by publisher]
Nutrition, dietary supplements and adenocarcinoma of the prostate.
Schultz C, Meier M, Schmid HP.
Maturitas. 2011 Oct 12. [Epub ahead of print]
PMID:
22001108
[PubMed - as supplied by publisher]
Interactions of Cu(I) with Selenium-Containing Amino Acids Determined by NMR, XAS, and DFT Studies.
Wang HC, Riahi M, Pothen J, Bayse CA, Riggs-Gelasco P, Brumaghim JL.
Inorg Chem. 2011 Oct 14. [Epub ahead of print]
PMID:
21999616
[PubMed - as supplied by publisher]
Effects of Basal Media and Supplements on Diethylstilbestrol-Treated Immature Mouse Primary Granulosa Cell Growth and Regulation of Steroidogenesis In Vitro.
Ding T, Luo A, Yang S, Lai Z, Wang Y, Shen W, Jiang J, Lu Y, Ma D, Wang S.
Reprod Domest Anim. 2011 Oct 15. doi: 10.1111/j.1439-0531.2011.01879.x. [Epub ahead of print]
PMID:
21999365
[PubMed - as supplied by publisher]
Demographic and lifestyle factors and selenium levels in men and women in the U.S.
Park K, Rimm E, Siscovick D, Spiegelman D, Morris JS, Mozaffarian D.
Nutr Res Pract. 2011 Aug;5(4):357-64. Epub 2011 Aug 31.
PMID:
21994531
[PubMed - in process]
New group 11 complexes with metal-selenium bonds of methyldiphenylphosphane selenide: a solid state, solution and theoretical investigation.
Pop A, Silvestru A, Gimeno MC, Laguna A, Kulcsar M, Arca M, Lippolis V, Pintus A.
Dalton Trans. 2011 Oct 13. [Epub ahead of print]
PMID:
21993712
[PubMed - as supplied by publisher] |
