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Isotopes of iodine

There are 37 known isotopes of iodine (53I) from 108I to 144I; all undergo radioactive decay except 127I, which is stable. Iodine is thus a monoisotopic element.

Isotopes of iodine (53I)
Main isotopes Decay
abun­dance half-life (t1/2) mode pro­duct
123I synth 13 h β+100% 123Te
124I synth 4.176 d ε 124Te
125I synth 59.40 d ε 125Te
127I 100% stable
129I trace 1.57×107 y β 129Xe
131I synth 8.02070 d β100% 131Xe
135I synth 6.57 h β 135Xe
Standard atomic weight Ar°(I)

Its longest-lived radioactive isotope, 129I, has a half-life of 15.7 million years, which is far too short for it to exist as a primordial nuclide. Cosmogenic sources of 129I produce very tiny quantities of it that are too small to affect atomic weight measurements; iodine is thus also a mononuclidic element—one that is found in nature only as a single nuclide. Most 129I derived radioactivity on Earth is man-made, an unwanted long-lived byproduct of early nuclear tests and nuclear fission accidents.

All other iodine radioisotopes have half-lives less than 60 days, and four of these are used as tracers and therapeutic agents in medicine. These are 123I, 124I, 125I, and 131I. All industrial production of radioactive iodine isotopes involves these four useful radionuclides.

The isotope 135I has a half-life less than seven hours, which is too short to be used in biology. Unavoidable in situ production of this isotope is important in nuclear reactor control, as it decays to 135Xe, the most powerful known neutron absorber, and the nuclide responsible for the so-called iodine pit phenomenon.

In addition to commercial production, 131I (half-life 8 days) is one of the common radioactive fission products of nuclear fission, and is thus produced inadvertently in very large amounts inside nuclear reactors. Due to its volatility, short half-life, and high abundance in fission products, 131I (along with the short-lived iodine isotope 132I, which is produced from the decay of 132Te with a half-life of 3 days) is responsible for the largest part of radioactive contamination during the first week after accidental environmental contamination from the radioactive waste from a nuclear power plant. Thus highly dosed iodine supplements (usually potassium iodide) are given to the populace after nuclear accidents or explosions (and in some cases prior to any such incident as a civil defense mechanism) to reduce the uptake of radioactive iodine compounds by the thyroid before the highly radioactive isotopes have had time to decay.

The portion of the total radiation activity (in air) contributed by each isotope versus time after the Chernobyl disaster, at the site. Note the prominence of radiation from I-131 and Te-132/I-132 for the first week. (Image using data from the OECD report, and the second edition of 'The radiochemical manual'.[3])

List of isotopes edit

Nuclide
[n 1]
Z N Isotopic mass (Da)
[n 2][n 3]
Half-life
[n 4]
Decay
mode

[n 5]
Daughter
isotope

[n 6][n 7]
Spin and
parity
[n 8][n 4]
Natural abundance (mole fraction)
Excitation energy[n 4] Normal proportion Range of variation
108I 53 55 107.94348(39)# 36(6) ms α (90%) 104Sb (1)#
β+ (9%) 108Te
p (1%) 107Te
109I 53 56 108.93815(11) 103(5) µs p (99.5%) 108Te (5/2+)
α (.5%) 105Sb
110I 53 57 109.93524(33)# 650(20) ms β+ (70.9%) 110Te 1+#
α (17%) 106Sb
β+, p (11%) 109Sb
β+, α (1.09%) 106Sn
111I 53 58 110.93028(32)# 2.5(2) s β+ (99.92%) 111Te (5/2+)#
α (.088%) 107Sb
112I 53 59 111.92797(23)# 3.42(11) s β+ (99.01%) 112Te
β+, p (.88%) 111Sb
β+, α (.104%) 108Sn
α (.0012%) 108Sb
113I 53 60 112.92364(6) 6.6(2) s β+ (100%) 113Te 5/2+#
α (3.3×10−7%) 109Sb
β+, α 109Sn
114I 53 61 113.92185(32)# 2.1(2) s β+ 114Te 1+
β+, p (rare) 113Sb
114mI 265.9(5) keV 6.2(5) s β+ (91%) 114Te (7)
IT (9%) 114I
115I 53 62 114.91805(3) 1.3(2) min β+ 115Te (5/2+)#
116I 53 63 115.91681(10) 2.91(15) s β+ 116Te 1+
116mI 400(50)# keV 3.27(16) µs (7−)
117I 53 64 116.91365(3) 2.22(4) min β+ 117Te (5/2)+
118I 53 65 117.913074(21) 13.7(5) min β+ 118Te 2−
118mI 190.1(10) keV 8.5(5) min β+ 118Te (7−)
IT (rare) 118I
119I 53 66 118.91007(3) 19.1(4) min β+ 119Te 5/2+
120I 53 67 119.910048(19) 81.6(2) min β+ 120Te 2−
120m1I 72.61(9) keV 228(15) ns (1+, 2+, 3+)
120m2I 320(15) keV 53(4) min β+ 120Te (7−)
121I 53 68 120.907367(11) 2.12(1) h β+ 121Te 5/2+
121mI 2376.9(4) keV 9.0(15) µs
122I 53 69 121.907589(6) 3.63(6) min β+ 122Te 1+
123I[n 9] 53 70 122.905589(4) 13.2235(19) h EC 123Te 5/2+
124I[n 9] 53 71 123.9062099(25) 4.1760(3) d β+ 124Te 2−
125I[n 9] 53 72 124.9046302(16) 59.400(10) d EC 125Te 5/2+
126I 53 73 125.905624(4) 12.93(5) d β+ (56.3%) 126Te 2−
β (43.7%) 126Xe
127I[n 10] 53 74 126.904473(4) Stable 5/2+ 1.0000
128I 53 75 127.905809(4) 24.99(2) min β (93.1%) 128Xe 1+
β+ (6.9%) 128Te
128m1I 137.850(4) keV 845(20) ns 4−
128m2I 167.367(5) keV 175(15) ns (6)−
129I[n 10][n 11] 53 76 128.904988(3) 1.57(4)×107 y β 129Xe 7/2+ Trace[n 12]
130I 53 77 129.906674(3) 12.36(1) h β 130Xe 5+
130m1I 39.9525(13) keV 8.84(6) min IT (84%) 130I 2+
β (16%) 130Xe
130m2I 69.5865(7) keV 133(7) ns (6)−
130m3I 82.3960(19) keV 315(15) ns -
130m4I 85.1099(10) keV 254(4) ns (6)−
131I[n 10][n 9] 53 78 130.9061246(12) 8.02070(11) d β 131Xe 7/2+
132I 53 79 131.907997(6) 2.295(13) h β 132Xe 4+
132mI 104(12) keV 1.387(15) h IT (86%) 132I (8−)
β (14%) 132Xe
133I 53 80 132.907797(5) 20.8(1) h β 133Xe 7/2+
133m1I 1634.174(17) keV 9(2) s IT 133I (19/2−)
133m2I 1729.160(17) keV ~170 ns (15/2−)
134I 53 81 133.909744(9) 52.5(2) min β 134Xe (4)+
134mI 316.49(22) keV 3.52(4) min IT (97.7%) 134I (8)−
β (2.3%) 134Xe
135I[n 13] 53 82 134.910048(8) 6.57(2) h β 135Xe 7/2+
136I 53 83 135.91465(5) 83.4(10) s β 136Xe (1−)
136mI 650(120) keV 46.9(10) s β 136Xe (6−)
137I 53 84 136.917871(30) 24.13(12) s β (92.86%) 137Xe (7/2+)
β, n (7.14%) 136Xe
138I 53 85 137.92235(9) 6.23(3) s β (94.54%) 138Xe (2−)
β, n (5.46%) 137Xe
139I 53 86 138.92610(3) 2.282(10) s β (90%) 139Xe 7/2+#
β, n (10%) 138Xe
140I 53 87 139.93100(21)# 860(40) ms β (90.7%) 140Xe (3)(−#)
β, n (9.3%) 139Xe
141I 53 88 140.93503(21)# 430(20) ms β (78%) 141Xe 7/2+#
β, n (22%) 140Xe
142I 53 89 141.94018(43)# ~200 ms β (75%) 142Xe 2−#
β, n (25%) 141Xe
143I 53 90 142.94456(43)# 100# ms [> 300 ns] β 143Xe 7/2+#
144I 53 91 143.94999(54)# 50# ms [> 300 ns] β 144Xe 1−#
This table header & footer:
  1. ^ mI – Excited nuclear isomer.
  2. ^ ( ) – Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits.
  3. ^ # – Atomic mass marked #: value and uncertainty derived not from purely experimental data, but at least partly from trends from the Mass Surface (TMS).
  4. ^ a b c # – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).
  5. ^ Modes of decay:
  6. ^ Bold italics symbol as daughter – Daughter product is nearly stable.
  7. ^ Bold symbol as daughter – Daughter product is stable.
  8. ^ ( ) spin value – Indicates spin with weak assignment arguments.
  9. ^ a b c d Has medical uses
  10. ^ a b c Fission product
  11. ^ Can be used to date certain early events in Solar System history and some use for dating groundwater
  12. ^ Cosmogenic nuclide, also found as nuclear contamination
  13. ^ Produced as a decay product of 135Te in nuclear reactors, in turn decays to 135Xe, which, if allowed to build up, can shut down reactors due to the iodine pit phenomenon

Notable radioisotopes edit

Radioisotopes of iodine are called radioactive iodine or radioiodine. Dozens exist, but about a half dozen are the most notable in applied sciences such as the life sciences and nuclear power, as detailed below. Mentions of radioiodine in health care contexts refer more often to iodine-131 than to other isotopes.

Of the many isotopes of iodine, only two are typically used in a medical setting: iodine-123 and iodine-131. Since 131I has both a beta and gamma decay mode, it can be used for radiotherapy or for imaging. 123I, which has no beta activity, is more suited for routine nuclear medicine imaging of the thyroid and other medical processes and less damaging internally to the patient. There are some situations in which iodine-124 and iodine-125 are also used in medicine.[4]

Due to preferential uptake of iodine by the thyroid, radioiodine is extensively used in imaging of and, in the case of 131I, destroying dysfunctional thyroid tissues. Other types of tissue selectively take up certain iodine-131-containing tissue-targeting and killing radiopharmaceutical agents (such as MIBG). Iodine-125 is the only other iodine radioisotope used in radiation therapy, but only as an implanted capsule in brachytherapy, where the isotope never has a chance to be released for chemical interaction with the body's tissues.

Iodine-123 and iodine-125 edit

The gamma-emitting isotopes iodine-123 (half-life 13 hours), and (less commonly) the longer-lived and less energetic iodine-125 (half-life 59 days) are used as nuclear imaging tracers to evaluate the anatomic and physiologic function of the thyroid. Abnormal results may be caused by disorders such as Graves' disease or Hashimoto's thyroiditis. Both isotopes decay by electron capture (EC) to the corresponding tellurium nuclides, but in neither case are these the metastable nuclides 123mTe and 125mTe (which are of higher energy, and are not produced from radioiodine). Instead, the excited tellurium nuclides decay immediately (half-life too short to detect). Following EC, the excited 123Te from 123I emits a high-speed 127 keV internal conversion electron (not a beta ray) about 13% of the time, but this does little cellular damage due to the nuclide's short half-life and the relatively small fraction of such events. In the remainder of cases, a 159 keV gamma ray is emitted, which is well-suited for gamma imaging.

Excited 125Te resulting from electron capture of 125I also emits a much lower-energy internal conversion electron (35.5 keV), which does relatively little damage due to its low energy, even though its emission is more common. The relatively low-energy gamma from 125I/125Te decay is poorly suited for imaging, but can still be seen, and this longer-lived isotope is necessary in tests that require several days of imaging, for example, fibrinogen scan imaging to detect blood clots.

Both 123I and 125I emit copious low energy Auger electrons after their decay, but these do not cause serious damage (double-stranded DNA breaks) in cells, unless the nuclide is incorporated into a medication that accumulates in the nucleus, or into DNA (this is never the case is clinical medicine, but it has been seen in experimental animal models).[5]

Iodine-125 is also commonly used by radiation oncologists in low dose rate brachytherapy in the treatment of cancer at sites other than the thyroid, especially in prostate cancer. When 125I is used therapeutically, it is encapsulated in titanium seeds and implanted in the area of the tumor, where it remains. The low energy of the gamma spectrum in this case limits radiation damage to tissues far from the implanted capsule. Iodine-125, due to its suitable longer half-life and less penetrating gamma spectrum, is also often preferred for laboratory tests that rely on iodine as a tracer that is counted by a gamma counter, such as in radioimmunoassaying.

125I is used as the radiolabel in investigating which ligands go to which plant pattern recognition receptors (PRRs).[6]

Iodine-124 edit

Iodine-124 is a proton-rich isotope of iodine with a half-life of 4.18 days. Its modes of decay are: 74.4% electron capture, 25.6% positron emission. 124I decays to 124Te. Iodine-124 can be made by numerous nuclear reactions via a cyclotron. The most common starting material used is 124Te.

Iodine-124 as the iodide salt can be used to directly image the thyroid using positron emission tomography (PET).[7] Iodine-124 can also be used as a PET radiotracer with a usefully longer half-life compared with fluorine-18.[8] In this use, the nuclide is chemically bonded to a pharmaceutical to form a positron-emitting radiopharmaceutical, and injected into the body, where again it is imaged by PET scan.

Iodine-129 edit

Iodine-129 (129I; half-life 15.7 million years) is a product of cosmic ray spallation on various isotopes of xenon in the atmosphere, in cosmic ray muon interaction with tellurium-130, and also uranium and plutonium fission, both in subsurface rocks and nuclear reactors. Artificial nuclear processes, in particular nuclear fuel reprocessing and atmospheric nuclear weapons tests, have now swamped the natural signal for this isotope. Nevertheless, it now serves as a groundwater tracer as indicator of nuclear waste dispersion into the natural environment. In a similar fashion, 129I was used in rainwater studies to track fission products following the Chernobyl disaster.

In some ways, 129I is similar to 36Cl. It is a soluble halogen, exists mainly as a non-sorbing anion, and is produced by cosmogenic, thermonuclear, and in-situ reactions. In hydrologic studies, 129I concentrations are usually reported as the ratio of 129I to total I (which is virtually all 127I). As is the case with 36Cl/Cl, 129I/I ratios in nature are quite small, 10−14 to 10−10 (peak thermonuclear 129I/I during the 1960s and 1970s reached about 10−7). 129I differs from 36Cl in that its half-life is longer (15.7 vs. 0.301 million years), it is highly biophilic, and occurs in multiple ionic forms (commonly, I and IO3), which have different chemical behaviors. This makes it fairly easy for 129I to enter the biosphere as it becomes incorporated into vegetation, soil, milk, animal tissue, etc. Excesses of stable 129Xe in meteorites have been shown to result from decay of "primordial" iodine-129 produced newly by the supernovas that created the dust and gas from which the solar system formed. This isotope has long decayed and is thus referred to as "extinct". Historically, 129I was the first extinct radionuclide to be identified as present in the early Solar System. Its decay is the basis of the I-Xe iodine-xenon radiometric dating scheme, which covers the first 85 million years of Solar System evolution.

Iodine-131 edit

 
A Pheochromocytoma is seen as a dark sphere in the center of the body (it is in the left adrenal gland). Image is by MIBG scintigraphy, with radiation from radioiodine in the MIBG. Two images are seen of the same patient from front and back. Note the dark image of the thyroid due to unwanted uptake of radioiodine from the medication by the thyroid gland in the neck. Accumulation at the sides of the head is from salivary gland uptake of iodide. Radioactivity is also seen in the bladder.

Iodine-131 (131
I
) is a beta-emitting isotope with a half-life of eight days, and comparatively energetic (190 keV average and 606 keV maximum energy) beta radiation, which penetrates 0.6 to 2.0 mm from the site of uptake. This beta radiation can be used for the destruction of thyroid nodules or hyperfunctioning thyroid tissue and for elimination of remaining thyroid tissue after surgery for the treatment of Graves' disease. The purpose of this therapy, which was first explored by Dr. Saul Hertz in 1941,[9] is to destroy thyroid tissue that could not be removed surgically. In this procedure, 131I is administered either intravenously or orally following a diagnostic scan. This procedure may also be used, with higher doses of radio-iodine, to treat patients with thyroid cancer.

The 131I is taken up into thyroid tissue and concentrated there. The beta particles emitted by the radioisotope destroys the associated thyroid tissue with little damage to surrounding tissues (more than 2.0 mm from the tissues absorbing the iodine). Due to similar destruction, 131I is the iodine radioisotope used in other water-soluble iodine-labeled radiopharmaceuticals (such as MIBG) used therapeutically to destroy tissues.

The high energy beta radiation (up to 606 keV) from 131I causes it to be the most carcinogenic of the iodine isotopes. It is thought to cause the majority of excess thyroid cancers seen after nuclear fission contamination (such as bomb fallout or severe nuclear reactor accidents like the Chernobyl disaster) However, these epidemiological effects are seen primarily in children, and treatment of adults and children with therapeutic 131I, and epidemiology of adults exposed to low-dose 131I has not demonstrated carcinogenicity.[10]

Iodine-135 edit

Iodine-135 is an isotope of iodine with a half-life of 6.6 hours. It is an important isotope from the viewpoint of nuclear reactor physics. It is produced in relatively large amounts as a fission product, and decays to xenon-135, which is a nuclear poison with a very large thermal neutron cross section, which is a cause of multiple complications in the control of nuclear reactors. The process of buildup of xenon-135 from accumulated iodine-135 can temporarily preclude a shut-down reactor from restarting. This is known as xenon poisoning or "falling into an iodine pit".

Iodine-128 and other isotopes edit

Iodine fission-produced isotopes not discussed above (iodine-128, iodine-130, iodine-132, and iodine-133) have half-lives of several hours or minutes, rendering them almost useless in other applicable areas. Those mentioned are neutron-rich and undergo beta decay to isotopes of xenon. Iodine-128 (half-life 25 minutes) can decay to either tellurium-128 by electron capture or to xenon-128 by beta decay. It has a specific radioactivity of 2.177×106 TBq/g.

Nonradioactive iodide (127I) as protection from unwanted radioiodine uptake by the thyroid edit

Colloquially, radioactive materials can be described as "hot," and non-radioactive materials can be described as "cold." There are instances in which cold iodide is administered to people in order to prevent the uptake of hot iodide by the thyroid gland. For example, blockade of thyroid iodine uptake with potassium iodide is used in nuclear medicine scintigraphy and therapy with some radioiodinated compounds that are not targeted to the thyroid, such as iobenguane (MIBG), which is used to image or treat neural tissue tumors, or iodinated fibrinogen, which is used in fibrinogen scans to investigate clotting. These compounds contain iodine, but not in the iodide form. However, since they may be ultimately metabolized or break down to radioactive iodide, it is common to administer non-radioactive potassium iodide to insure that metabolites of these radiopharmaceuticals is not sequestered by thyroid gland and inadvertently administer a radiological dose to that tissue.

Potassium iodide has been distributed to populations exposed to nuclear fission accidents such as the Chernobyl disaster. The iodide solution SSKI, a saturated solution of potassium (K) iodide in water, has been used to block absorption of the radioiodine (it has no effect on other radioisotopes from fission). Tablets containing potassium iodide are now also manufactured and stocked in central disaster sites by some governments for this purpose. In theory, many harmful late-cancer effects of nuclear fallout might be prevented in this way, since an excess of thyroid cancers, presumably due to radioiodine uptake, is the only proven radioisotope contamination effect after a fission accident, or from contamination by fallout from an atomic bomb (prompt radiation from the bomb also causes other cancers, such as leukemias, directly). Taking large amounts of iodide saturates thyroid receptors and prevents uptake of most radioactive iodine-131 that may be present from fission product exposure (although it does not protect from other radioisotopes, nor from any other form of direct radiation). The protective effect of KI lasts approximately 24 hours, so must be dosed daily until a risk of significant exposure to radioiodines from fission products no longer exists.[11][12] Iodine-131 (the most common radioiodine contaminant in fallout) also decays relatively rapidly with a half-life of eight days, so that 99.95% of the original radioiodine has vanished after three months.

References edit

  • Isotope masses from:
    • Audi, Georges; Bersillon, Olivier; Blachot, Jean; Wapstra, Aaldert Hendrik (2003), "The NUBASE evaluation of nuclear and decay properties", Nuclear Physics A, 729: 3–128, Bibcode:2003NuPhA.729....3A, doi:10.1016/j.nuclphysa.2003.11.001
  • Isotopic compositions and standard atomic masses from:
    • de Laeter, John Robert; Böhlke, John Karl; De Bièvre, Paul; Hidaka, Hiroshi; Peiser, H. Steffen; Rosman, Kevin J. R.; Taylor, Philip D. P. (2003). "Atomic weights of the elements. Review 2000 (IUPAC Technical Report)". Pure and Applied Chemistry. 75 (6): 683–800. doi:10.1351/pac200375060683.
    • Wieser, Michael E. (2006). "Atomic weights of the elements 2005 (IUPAC Technical Report)". Pure and Applied Chemistry. 78 (11): 2051–2066. doi:10.1351/pac200678112051.
  • "News & Notices: Standard Atomic Weights Revised". International Union of Pure and Applied Chemistry. 19 October 2005.
  • Half-life, spin, and isomer data selected from the following sources.
  1. ^ "Standard Atomic Weights: Iodine". CIAAW. 1985.
  2. ^ Prohaska, Thomas; Irrgeher, Johanna; Benefield, Jacqueline; Böhlke, John K.; Chesson, Lesley A.; Coplen, Tyler B.; Ding, Tiping; Dunn, Philip J. H.; Gröning, Manfred; Holden, Norman E.; Meijer, Harro A. J. (2022-05-04). "Standard atomic weights of the elements 2021 (IUPAC Technical Report)". Pure and Applied Chemistry. doi:10.1515/pac-2019-0603. ISSN 1365-3075.
  3. ^ . Archived from the original on 2007-01-21. Retrieved 2009-05-13.
  4. ^ Augustine George; James T Lane; Arlen D Meyers (January 17, 2013). "Radioactive Iodine Uptake Testing". Medscape.
  5. ^ V. R. Narra; et al. (1992). "Radiotoxicity of Some Iodine-123, Iodine-125, and Iodine-131-Labeled Compounds in Mouse Testes: Implications for Radiopharmaceutical Design" (PDF). Journal of Nuclear Medicine. 33 (12): 2196–201. PMID 1460515.
  6. ^ Boutrot, Freddy; Zipfel, Cyril (2017-08-04). "Function, Discovery, and Exploitation of Plant Pattern Recognition Receptors for Broad-Spectrum Disease Resistance". Annual Review of Phytopathology. Annual Reviews. 55 (1): 257–286. doi:10.1146/annurev-phyto-080614-120106. ISSN 0066-4286. PMID 28617654.
  7. ^ E. Rault; et al. (2007). "Comparison of Image Quality of Different Iodine Isotopes (I-123, I-124, and I-131)". Cancer Biotherapy & Radiopharmaceuticals. 22 (3): 423–430. doi:10.1089/cbr.2006.323. PMID 17651050.
  8. ^ BV Cyclotron VU, Amsterdam, 2016, Information on Iodine-124 for PET 2017-10-26 at the Wayback Machine
  9. ^ Hertz, Barbara; Schuleller, Kristin (2010). "Saul Hertz, MD (1905 - 1950) A Pioneer in the Use of Radioactive Iodine". Endocrine Practice. 16 (4): 713–715. doi:10.4158/EP10065.CO. PMID 20350908.
  10. ^ Robbins, Jacob; Schneider, Arthur B. (2000). "Thyroid cancer following exposure to radioactive iodine". Reviews in Endocrine and Metabolic Disorders. 1 (3): 197–203. doi:10.1023/A:1010031115233. ISSN 1389-9155. PMID 11705004. S2CID 13575769.
  11. ^ "Frequently Asked Questions on Potassium Iodide". Food and Drug Administration. Retrieved 2009-06-06.
  12. ^ . Federal Register. Food and Drug Administration. Archived from the original on 2011-10-02. Retrieved 2009-06-06.

External links edit

  • Iodine-128, Iodine-130, Iodine-132 data from 'Wolframalpha'

isotopes, iodine, this, article, needs, additional, citations, verification, please, help, improve, this, article, adding, citations, reliable, sources, unsourced, material, challenged, removed, find, sources, news, newspapers, books, scholar, jstor, 2018, lea. This article needs additional citations for verification Please help improve this article by adding citations to reliable sources Unsourced material may be challenged and removed Find sources Isotopes of iodine news newspapers books scholar JSTOR May 2018 Learn how and when to remove this template message There are 37 known isotopes of iodine 53I from 108I to 144I all undergo radioactive decay except 127I which is stable Iodine is thus a monoisotopic element Isotopes of iodine 53I Main isotopes Decayabun dance half life t1 2 mode pro duct123I synth 13 h b 100 123Te124I synth 4 176 d e 124Te125I synth 59 40 d e 125Te127I 100 stable129I trace 1 57 107 y b 129Xe131I synth 8 02070 d b 100 131Xe135I synth 6 57 h b 135XeStandard atomic weight Ar I 126 90447 0 00003 1 126 90 0 01 abridged 2 viewtalkeditIts longest lived radioactive isotope 129I has a half life of 15 7 million years which is far too short for it to exist as a primordial nuclide Cosmogenic sources of 129I produce very tiny quantities of it that are too small to affect atomic weight measurements iodine is thus also a mononuclidic element one that is found in nature only as a single nuclide Most 129I derived radioactivity on Earth is man made an unwanted long lived byproduct of early nuclear tests and nuclear fission accidents All other iodine radioisotopes have half lives less than 60 days and four of these are used as tracers and therapeutic agents in medicine These are 123I 124I 125I and 131I All industrial production of radioactive iodine isotopes involves these four useful radionuclides The isotope 135I has a half life less than seven hours which is too short to be used in biology Unavoidable in situ production of this isotope is important in nuclear reactor control as it decays to 135Xe the most powerful known neutron absorber and the nuclide responsible for the so called iodine pit phenomenon In addition to commercial production 131I half life 8 days is one of the common radioactive fission products of nuclear fission and is thus produced inadvertently in very large amounts inside nuclear reactors Due to its volatility short half life and high abundance in fission products 131I along with the short lived iodine isotope 132I which is produced from the decay of 132Te with a half life of 3 days is responsible for the largest part of radioactive contamination during the first week after accidental environmental contamination from the radioactive waste from a nuclear power plant Thus highly dosed iodine supplements usually potassium iodide are given to the populace after nuclear accidents or explosions and in some cases prior to any such incident as a civil defense mechanism to reduce the uptake of radioactive iodine compounds by the thyroid before the highly radioactive isotopes have had time to decay The portion of the total radiation activity in air contributed by each isotope versus time after the Chernobyl disaster at the site Note the prominence of radiation from I 131 and Te 132 I 132 for the first week Image using data from the OECD report and the second edition of The radiochemical manual 3 Contents 1 List of isotopes 2 Notable radioisotopes 2 1 Iodine 123 and iodine 125 2 2 Iodine 124 2 3 Iodine 129 2 4 Iodine 131 2 5 Iodine 135 2 6 Iodine 128 and other isotopes 3 Nonradioactive iodide 127I as protection from unwanted radioiodine uptake by the thyroid 4 References 5 External linksList of isotopes editNuclide n 1 Z N Isotopic mass Da n 2 n 3 Half life n 4 Decaymode n 5 Daughterisotope n 6 n 7 Spin andparity n 8 n 4 Natural abundance mole fraction Excitation energy n 4 Normal proportion Range of variation108I 53 55 107 94348 39 36 6 ms a 90 104Sb 1 b 9 108Tep 1 107Te109I 53 56 108 93815 11 103 5 µs p 99 5 108Te 5 2 a 5 105Sb110I 53 57 109 93524 33 650 20 ms b 70 9 110Te 1 a 17 106Sbb p 11 109Sbb a 1 09 106Sn111I 53 58 110 93028 32 2 5 2 s b 99 92 111Te 5 2 a 088 107Sb112I 53 59 111 92797 23 3 42 11 s b 99 01 112Teb p 88 111Sbb a 104 108Sna 0012 108Sb113I 53 60 112 92364 6 6 6 2 s b 100 113Te 5 2 a 3 3 10 7 109Sbb a 109Sn114I 53 61 113 92185 32 2 1 2 s b 114Te 1 b p rare 113Sb114mI 265 9 5 keV 6 2 5 s b 91 114Te 7 IT 9 114I115I 53 62 114 91805 3 1 3 2 min b 115Te 5 2 116I 53 63 115 91681 10 2 91 15 s b 116Te 1 116mI 400 50 keV 3 27 16 µs 7 117I 53 64 116 91365 3 2 22 4 min b 117Te 5 2 118I 53 65 117 913074 21 13 7 5 min b 118Te 2 118mI 190 1 10 keV 8 5 5 min b 118Te 7 IT rare 118I119I 53 66 118 91007 3 19 1 4 min b 119Te 5 2 120I 53 67 119 910048 19 81 6 2 min b 120Te 2 120m1I 72 61 9 keV 228 15 ns 1 2 3 120m2I 320 15 keV 53 4 min b 120Te 7 121I 53 68 120 907367 11 2 12 1 h b 121Te 5 2 121mI 2376 9 4 keV 9 0 15 µs122I 53 69 121 907589 6 3 63 6 min b 122Te 1 123I n 9 53 70 122 905589 4 13 2235 19 h EC 123Te 5 2 124I n 9 53 71 123 9062099 25 4 1760 3 d b 124Te 2 125I n 9 53 72 124 9046302 16 59 400 10 d EC 125Te 5 2 126I 53 73 125 905624 4 12 93 5 d b 56 3 126Te 2 b 43 7 126Xe127I n 10 53 74 126 904473 4 Stable 5 2 1 0000128I 53 75 127 905809 4 24 99 2 min b 93 1 128Xe 1 b 6 9 128Te128m1I 137 850 4 keV 845 20 ns 4 128m2I 167 367 5 keV 175 15 ns 6 129I n 10 n 11 53 76 128 904988 3 1 57 4 107 y b 129Xe 7 2 Trace n 12 130I 53 77 129 906674 3 12 36 1 h b 130Xe 5 130m1I 39 9525 13 keV 8 84 6 min IT 84 130I 2 b 16 130Xe130m2I 69 5865 7 keV 133 7 ns 6 130m3I 82 3960 19 keV 315 15 ns 130m4I 85 1099 10 keV 254 4 ns 6 131I n 10 n 9 53 78 130 9061246 12 8 02070 11 d b 131Xe 7 2 132I 53 79 131 907997 6 2 295 13 h b 132Xe 4 132mI 104 12 keV 1 387 15 h IT 86 132I 8 b 14 132Xe133I 53 80 132 907797 5 20 8 1 h b 133Xe 7 2 133m1I 1634 174 17 keV 9 2 s IT 133I 19 2 133m2I 1729 160 17 keV 170 ns 15 2 134I 53 81 133 909744 9 52 5 2 min b 134Xe 4 134mI 316 49 22 keV 3 52 4 min IT 97 7 134I 8 b 2 3 134Xe135I n 13 53 82 134 910048 8 6 57 2 h b 135Xe 7 2 136I 53 83 135 91465 5 83 4 10 s b 136Xe 1 136mI 650 120 keV 46 9 10 s b 136Xe 6 137I 53 84 136 917871 30 24 13 12 s b 92 86 137Xe 7 2 b n 7 14 136Xe138I 53 85 137 92235 9 6 23 3 s b 94 54 138Xe 2 b n 5 46 137Xe139I 53 86 138 92610 3 2 282 10 s b 90 139Xe 7 2 b n 10 138Xe140I 53 87 139 93100 21 860 40 ms b 90 7 140Xe 3 b n 9 3 139Xe141I 53 88 140 93503 21 430 20 ms b 78 141Xe 7 2 b n 22 140Xe142I 53 89 141 94018 43 200 ms b 75 142Xe 2 b n 25 141Xe143I 53 90 142 94456 43 100 ms gt 300 ns b 143Xe 7 2 144I 53 91 143 94999 54 50 ms gt 300 ns b 144Xe 1 This table header amp footer view mI Excited nuclear isomer Uncertainty 1s is given in concise form in parentheses after the corresponding last digits Atomic mass marked value and uncertainty derived not from purely experimental data but at least partly from trends from the Mass Surface TMS a b c Values marked are not purely derived from experimental data but at least partly from trends of neighboring nuclides TNN Modes of decay EC Electron captureIT Isomeric transitionn Neutron emissionp Proton emission Bold italics symbol as daughter Daughter product is nearly stable Bold symbol as daughter Daughter product is stable spin value Indicates spin with weak assignment arguments a b c d Has medical uses a b c Fission product Can be used to date certain early events in Solar System history and some use for dating groundwater Cosmogenic nuclide also found as nuclear contamination Produced as a decay product of 135Te in nuclear reactors in turn decays to 135Xe which if allowed to build up can shut down reactors due to the iodine pit phenomenonNotable radioisotopes editThis section needs additional citations for verification Please help improve this article by adding citations to reliable sources in this section Unsourced material may be challenged and removed Find sources Isotopes of iodine news newspapers books scholar JSTOR May 2018 Learn how and when to remove this template message Radioisotopes of iodine are called radioactive iodine or radioiodine Dozens exist but about a half dozen are the most notable in applied sciences such as the life sciences and nuclear power as detailed below Mentions of radioiodine in health care contexts refer more often to iodine 131 than to other isotopes Of the many isotopes of iodine only two are typically used in a medical setting iodine 123 and iodine 131 Since 131I has both a beta and gamma decay mode it can be used for radiotherapy or for imaging 123I which has no beta activity is more suited for routine nuclear medicine imaging of the thyroid and other medical processes and less damaging internally to the patient There are some situations in which iodine 124 and iodine 125 are also used in medicine 4 Due to preferential uptake of iodine by the thyroid radioiodine is extensively used in imaging of and in the case of 131I destroying dysfunctional thyroid tissues Other types of tissue selectively take up certain iodine 131 containing tissue targeting and killing radiopharmaceutical agents such as MIBG Iodine 125 is the only other iodine radioisotope used in radiation therapy but only as an implanted capsule in brachytherapy where the isotope never has a chance to be released for chemical interaction with the body s tissues Iodine 123 and iodine 125 edit Main articles Iodine 123 and Iodine 125 The gamma emitting isotopes iodine 123 half life 13 hours and less commonly the longer lived and less energetic iodine 125 half life 59 days are used as nuclear imaging tracers to evaluate the anatomic and physiologic function of the thyroid Abnormal results may be caused by disorders such as Graves disease or Hashimoto s thyroiditis Both isotopes decay by electron capture EC to the corresponding tellurium nuclides but in neither case are these the metastable nuclides 123mTe and 125mTe which are of higher energy and are not produced from radioiodine Instead the excited tellurium nuclides decay immediately half life too short to detect Following EC the excited 123Te from 123I emits a high speed 127 keV internal conversion electron not a beta ray about 13 of the time but this does little cellular damage due to the nuclide s short half life and the relatively small fraction of such events In the remainder of cases a 159 keV gamma ray is emitted which is well suited for gamma imaging Excited 125Te resulting from electron capture of 125I also emits a much lower energy internal conversion electron 35 5 keV which does relatively little damage due to its low energy even though its emission is more common The relatively low energy gamma from 125I 125Te decay is poorly suited for imaging but can still be seen and this longer lived isotope is necessary in tests that require several days of imaging for example fibrinogen scan imaging to detect blood clots Both 123I and 125I emit copious low energy Auger electrons after their decay but these do not cause serious damage double stranded DNA breaks in cells unless the nuclide is incorporated into a medication that accumulates in the nucleus or into DNA this is never the case is clinical medicine but it has been seen in experimental animal models 5 Iodine 125 is also commonly used by radiation oncologists in low dose rate brachytherapy in the treatment of cancer at sites other than the thyroid especially in prostate cancer When 125I is used therapeutically it is encapsulated in titanium seeds and implanted in the area of the tumor where it remains The low energy of the gamma spectrum in this case limits radiation damage to tissues far from the implanted capsule Iodine 125 due to its suitable longer half life and less penetrating gamma spectrum is also often preferred for laboratory tests that rely on iodine as a tracer that is counted by a gamma counter such as in radioimmunoassaying 125I is used as the radiolabel in investigating which ligands go to which plant pattern recognition receptors PRRs 6 Iodine 124 edit Iodine 124 is a proton rich isotope of iodine with a half life of 4 18 days Its modes of decay are 74 4 electron capture 25 6 positron emission 124I decays to 124Te Iodine 124 can be made by numerous nuclear reactions via a cyclotron The most common starting material used is 124Te Iodine 124 as the iodide salt can be used to directly image the thyroid using positron emission tomography PET 7 Iodine 124 can also be used as a PET radiotracer with a usefully longer half life compared with fluorine 18 8 In this use the nuclide is chemically bonded to a pharmaceutical to form a positron emitting radiopharmaceutical and injected into the body where again it is imaged by PET scan Iodine 129 edit Main article Iodine 129 Iodine 129 129I half life 15 7 million years is a product of cosmic ray spallation on various isotopes of xenon in the atmosphere in cosmic ray muon interaction with tellurium 130 and also uranium and plutonium fission both in subsurface rocks and nuclear reactors Artificial nuclear processes in particular nuclear fuel reprocessing and atmospheric nuclear weapons tests have now swamped the natural signal for this isotope Nevertheless it now serves as a groundwater tracer as indicator of nuclear waste dispersion into the natural environment In a similar fashion 129I was used in rainwater studies to track fission products following the Chernobyl disaster In some ways 129I is similar to 36Cl It is a soluble halogen exists mainly as a non sorbing anion and is produced by cosmogenic thermonuclear and in situ reactions In hydrologic studies 129I concentrations are usually reported as the ratio of 129I to total I which is virtually all 127I As is the case with 36Cl Cl 129I I ratios in nature are quite small 10 14 to 10 10 peak thermonuclear 129I I during the 1960s and 1970s reached about 10 7 129I differs from 36Cl in that its half life is longer 15 7 vs 0 301 million years it is highly biophilic and occurs in multiple ionic forms commonly I and IO3 which have different chemical behaviors This makes it fairly easy for 129I to enter the biosphere as it becomes incorporated into vegetation soil milk animal tissue etc Excesses of stable 129Xe in meteorites have been shown to result from decay of primordial iodine 129 produced newly by the supernovas that created the dust and gas from which the solar system formed This isotope has long decayed and is thus referred to as extinct Historically 129I was the first extinct radionuclide to be identified as present in the early Solar System Its decay is the basis of the I Xe iodine xenon radiometric dating scheme which covers the first 85 million years of Solar System evolution Iodine 131 edit Main article Iodine 131 nbsp A Pheochromocytoma is seen as a dark sphere in the center of the body it is in the left adrenal gland Image is by MIBG scintigraphy with radiation from radioiodine in the MIBG Two images are seen of the same patient from front and back Note the dark image of the thyroid due to unwanted uptake of radioiodine from the medication by the thyroid gland in the neck Accumulation at the sides of the head is from salivary gland uptake of iodide Radioactivity is also seen in the bladder Iodine 131 131 I is a beta emitting isotope with a half life of eight days and comparatively energetic 190 keV average and 606 keV maximum energy beta radiation which penetrates 0 6 to 2 0 mm from the site of uptake This beta radiation can be used for the destruction of thyroid nodules or hyperfunctioning thyroid tissue and for elimination of remaining thyroid tissue after surgery for the treatment of Graves disease The purpose of this therapy which was first explored by Dr Saul Hertz in 1941 9 is to destroy thyroid tissue that could not be removed surgically In this procedure 131I is administered either intravenously or orally following a diagnostic scan This procedure may also be used with higher doses of radio iodine to treat patients with thyroid cancer The 131I is taken up into thyroid tissue and concentrated there The beta particles emitted by the radioisotope destroys the associated thyroid tissue with little damage to surrounding tissues more than 2 0 mm from the tissues absorbing the iodine Due to similar destruction 131I is the iodine radioisotope used in other water soluble iodine labeled radiopharmaceuticals such as MIBG used therapeutically to destroy tissues The high energy beta radiation up to 606 keV from 131I causes it to be the most carcinogenic of the iodine isotopes It is thought to cause the majority of excess thyroid cancers seen after nuclear fission contamination such as bomb fallout or severe nuclear reactor accidents like the Chernobyl disaster However these epidemiological effects are seen primarily in children and treatment of adults and children with therapeutic 131I and epidemiology of adults exposed to low dose 131I has not demonstrated carcinogenicity 10 Iodine 135 edit Iodine 135 is an isotope of iodine with a half life of 6 6 hours It is an important isotope from the viewpoint of nuclear reactor physics It is produced in relatively large amounts as a fission product and decays to xenon 135 which is a nuclear poison with a very large thermal neutron cross section which is a cause of multiple complications in the control of nuclear reactors The process of buildup of xenon 135 from accumulated iodine 135 can temporarily preclude a shut down reactor from restarting This is known as xenon poisoning or falling into an iodine pit Iodine 128 and other isotopes edit Iodine fission produced isotopes not discussed above iodine 128 iodine 130 iodine 132 and iodine 133 have half lives of several hours or minutes rendering them almost useless in other applicable areas Those mentioned are neutron rich and undergo beta decay to isotopes of xenon Iodine 128 half life 25 minutes can decay to either tellurium 128 by electron capture or to xenon 128 by beta decay It has a specific radioactivity of 2 177 106 TBq g Nonradioactive iodide 127I as protection from unwanted radioiodine uptake by the thyroid editThis section possibly contains original research Please improve it by verifying the claims made and adding inline citations Statements consisting only of original research should be removed May 2018 Learn how and when to remove this template message Colloquially radioactive materials can be described as hot and non radioactive materials can be described as cold There are instances in which cold iodide is administered to people in order to prevent the uptake of hot iodide by the thyroid gland For example blockade of thyroid iodine uptake with potassium iodide is used in nuclear medicine scintigraphy and therapy with some radioiodinated compounds that are not targeted to the thyroid such as iobenguane MIBG which is used to image or treat neural tissue tumors or iodinated fibrinogen which is used in fibrinogen scans to investigate clotting These compounds contain iodine but not in the iodide form However since they may be ultimately metabolized or break down to radioactive iodide it is common to administer non radioactive potassium iodide to insure that metabolites of these radiopharmaceuticals is not sequestered by thyroid gland and inadvertently administer a radiological dose to that tissue Potassium iodide has been distributed to populations exposed to nuclear fission accidents such as the Chernobyl disaster The iodide solution SSKI a saturated solution of potassium K iodide in water has been used to block absorption of the radioiodine it has no effect on other radioisotopes from fission Tablets containing potassium iodide are now also manufactured and stocked in central disaster sites by some governments for this purpose In theory many harmful late cancer effects of nuclear fallout might be prevented in this way since an excess of thyroid cancers presumably due to radioiodine uptake is the only proven radioisotope contamination effect after a fission accident or from contamination by fallout from an atomic bomb prompt radiation from the bomb also causes other cancers such as leukemias directly Taking large amounts of iodide saturates thyroid receptors and prevents uptake of most radioactive iodine 131 that may be present from fission product exposure although it does not protect from other radioisotopes nor from any other form of direct radiation The protective effect of KI lasts approximately 24 hours so must be dosed daily until a risk of significant exposure to radioiodines from fission products no longer exists 11 12 Iodine 131 the most common radioiodine contaminant in fallout also decays relatively rapidly with a half life of eight days so that 99 95 of the original radioiodine has vanished after three months References editIsotope masses from Audi Georges Bersillon Olivier Blachot Jean Wapstra Aaldert Hendrik 2003 The NUBASE evaluation of nuclear and decay properties Nuclear Physics A 729 3 128 Bibcode 2003NuPhA 729 3A doi 10 1016 j nuclphysa 2003 11 001 Isotopic compositions and standard atomic masses from de Laeter John Robert Bohlke John Karl De Bievre Paul Hidaka Hiroshi Peiser H Steffen Rosman Kevin J R Taylor Philip D P 2003 Atomic weights of the elements Review 2000 IUPAC Technical Report Pure and Applied Chemistry 75 6 683 800 doi 10 1351 pac200375060683 Wieser Michael E 2006 Atomic weights of the elements 2005 IUPAC Technical Report Pure and Applied Chemistry 78 11 2051 2066 doi 10 1351 pac200678112051 News amp Notices Standard Atomic Weights Revised International Union of Pure and Applied Chemistry 19 October 2005 Half life spin and isomer data selected from the following sources Audi Georges Bersillon Olivier Blachot Jean Wapstra Aaldert Hendrik 2003 The NUBASE evaluation of nuclear and decay properties Nuclear Physics A 729 3 128 Bibcode 2003NuPhA 729 3A doi 10 1016 j nuclphysa 2003 11 001 National Nuclear Data Center NuDat 2 x database Brookhaven National Laboratory Holden Norman E 2004 11 Table of the Isotopes In Lide David R ed CRC Handbook of Chemistry and Physics 85th ed Boca Raton Florida CRC Press ISBN 978 0 8493 0485 9 Standard Atomic Weights Iodine CIAAW 1985 Prohaska Thomas Irrgeher Johanna Benefield Jacqueline Bohlke John K Chesson Lesley A Coplen Tyler B Ding Tiping Dunn Philip J H Groning Manfred Holden Norman E Meijer Harro A J 2022 05 04 Standard atomic weights of the elements 2021 IUPAC Technical Report Pure and Applied Chemistry doi 10 1515 pac 2019 0603 ISSN 1365 3075 Nuclear Data Evaluation Lab Archived from the original on 2007 01 21 Retrieved 2009 05 13 Augustine George James T Lane Arlen D Meyers January 17 2013 Radioactive Iodine Uptake Testing Medscape V R Narra et al 1992 Radiotoxicity of Some Iodine 123 Iodine 125 and Iodine 131 Labeled Compounds in Mouse Testes Implications for Radiopharmaceutical Design PDF Journal of Nuclear Medicine 33 12 2196 201 PMID 1460515 Boutrot Freddy Zipfel Cyril 2017 08 04 Function Discovery and Exploitation of Plant Pattern Recognition Receptors for Broad Spectrum Disease Resistance Annual Review of Phytopathology Annual Reviews 55 1 257 286 doi 10 1146 annurev phyto 080614 120106 ISSN 0066 4286 PMID 28617654 E Rault et al 2007 Comparison of Image Quality of Different Iodine Isotopes I 123 I 124 and I 131 Cancer Biotherapy amp Radiopharmaceuticals 22 3 423 430 doi 10 1089 cbr 2006 323 PMID 17651050 BV Cyclotron VU Amsterdam 2016 Information on Iodine 124 for PET Archived 2017 10 26 at the Wayback Machine Hertz Barbara Schuleller Kristin 2010 Saul Hertz MD 1905 1950 A Pioneer in the Use of Radioactive Iodine Endocrine Practice 16 4 713 715 doi 10 4158 EP10065 CO PMID 20350908 Robbins Jacob Schneider Arthur B 2000 Thyroid cancer following exposure to radioactive iodine Reviews in Endocrine and Metabolic Disorders 1 3 197 203 doi 10 1023 A 1010031115233 ISSN 1389 9155 PMID 11705004 S2CID 13575769 Frequently Asked Questions on Potassium Iodide Food and Drug Administration Retrieved 2009 06 06 Potassium Iodide as a Thyroid Blocking Agent in Radiation Emergencies Federal Register Food and Drug Administration Archived from the original on 2011 10 02 Retrieved 2009 06 06 External links editIodine isotopes data from The Berkeley Laboratory Isotopes Project s Iodine 128 Iodine 130 Iodine 132 data from Wolframalpha Retrieved from https en wikipedia org w index php title Isotopes of iodine amp oldid 1190124806 Iodine 140, wikipedia, wiki, book, books, library,

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