Isotopes of gallium
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Natural gallium (31Ga) consists of a mixture of two stable isotopes: gallium-69 and gallium-71. Synthetic radioisotopes are known with atomic masses ranging from 60 to 89, along with seven nuclear isomers. Most of the isotopes with atomic mass numbers below 69 decay by electron capture and positron emission to isotopes of zinc, while most of the isotopes with masses above 71 beta decay to isotopes of germanium.
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| Standard atomic weight Ar°(Ga) | |||||||||||||||||||||||||||||||||||||||||||||||||||||
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The medically important radioisotopes are gallium-67 and gallium-68, used for imaging, and further described below.
List of isotopes
| Nuclide [n 1] |
Z | N | Isotopic mass (Da)[4] [n 2][n 3] |
Discovery year[5][6] |
Half-life[1] |
Decay mode[1] [n 4] |
Daughter isotope [n 5] |
Spin and parity[1] [n 6][n 7] |
Natural abundance (mole fraction) | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Excitation energy | Normal proportion[1] | Range of variation | |||||||||||||||||
| 60Ga | 31 | 29 | 59.957041(16)[7] | 1995 | 69.4(2) ms[7] | β+ (98.4%) | 60Zn | (2+) | |||||||||||
| β+, p (1.6%) | 59Cu | ||||||||||||||||||
| β+, α? (<0.023%) | 56Ni | ||||||||||||||||||
| 61Ga | 31 | 30 | 60.949399(41) | 1987 | 165.9(25) ms | β+ | 61Zn | 3/2− | |||||||||||
| β+, p? (<0.25%) | 60Cu | ||||||||||||||||||
| 62Ga | 31 | 31 | 61.94418964(68) | 1978 | 116.122(21) ms | β+ | 62Zn | 0+ | |||||||||||
| 63Ga | 31 | 32 | 62.9392942(14) | 1965 | 32.4(5) s | β+ | 63Zn | 3/2− | |||||||||||
| 64Ga | 31 | 33 | 63.9368404(15) | 1953 | 2.627(12) min | β+ | 64Zn | 0(+#) | |||||||||||
| 64mGa | 42.85(8) keV | 1974 | 21.9(7) μs | IT | 64Ga | (2+) | |||||||||||||
| 65Ga | 31 | 34 | 64.93273442(85) | 1938 | 15.133(28) min | β+ | 65Zn | 3/2− | |||||||||||
| 66Ga | 31 | 35 | 65.9315898(12) | 1937 | 9.304(8) h | β+ | 66Zn | 0+ | |||||||||||
| 67Ga[n 8] | 31 | 36 | 66.9282023(13) | 1938 | 3.2617(4) d | EC | 67Zn | 3/2− | |||||||||||
| 68Ga[n 8] | 31 | 37 | 67.9279802(15) | 1937 | 67.842(16) min | β+ | 68Zn | 1+ | |||||||||||
| 69Ga | 31 | 38 | 68.9255735(13) | 1923 | Stable | 3/2− | 0.60108(50) | ||||||||||||
| 70Ga | 31 | 39 | 69.9260219(13) | 1937 | 21.14(5) min | β− (99.59%) | 70Ge | 1+ | |||||||||||
| EC (0.41%) | 70Zn | ||||||||||||||||||
| 71Ga | 31 | 40 | 70.92470255(87) | 1923 | Stable | 3/2− | 0.39892(50) | ||||||||||||
| 72Ga | 31 | 41 | 71.92636745(88) | 1939 | 14.025(10) h | β− | 72Ge | 3− | |||||||||||
| 72mGa | 119.66(5) keV | 1959 | 39.68(13) ms | IT | 72Ga | (0+) | |||||||||||||
| 73Ga | 31 | 42 | 72.9251747(18) | 1951 | 4.86(3) h | β− | 73Ge | 1/2− | |||||||||||
| 73mGa | 0.15(9) keV | (2017)[n 9] | <200 ms | IT? | 73Ga | 3/2− | |||||||||||||
| β− | 73Ge | ||||||||||||||||||
| 74Ga | 31 | 43 | 73.9269457(32) | 1956 | 8.12(12) min | β− | 74Ge | (3−) | |||||||||||
| 74mGa | 59.571(14) keV | 1974 | 9.5(10) s | IT (>75%) | 74Ga | (0)(+#) | |||||||||||||
| β−? (<25%) | 74Ge | ||||||||||||||||||
| 75Ga | 31 | 44 | 74.92650448(72) | 1960 | 126(2) s | β− | 75Ge | 3/2− | |||||||||||
| 76Ga | 31 | 45 | 75.9288276(21) | 1961 | 30.6(6) s | β− | 76Ge | 2− | |||||||||||
| 77Ga | 31 | 46 | 76.9291543(26) | 1968 | 13.2(2) s | β− | 77mGe (88%) | 3/2− | |||||||||||
| 77Ge (12%) | |||||||||||||||||||
| 78Ga | 31 | 47 | 77.9316109(11) | 1972 | 5.09(5) s | β− | 78Ge | 2− | |||||||||||
| 78mGa | 498.9(5) keV | 2009 | 110(3) ns | IT | 78Ga | ||||||||||||||
| 79Ga | 31 | 48 | 78.9328516(13) | 1974 | 2.848(3) s | β− (99.911%) | 79Ge | 3/2− | |||||||||||
| β−, n (0.089%) | 78Ge | ||||||||||||||||||
| 80Ga | 31 | 49 | 79.9364208(31) | 1974 | 1.9(1) s | β− (99.14%) | 80Ge | 6− | |||||||||||
| β−, n (.86%) | 79Ge | ||||||||||||||||||
| 80mGa[n 10] | 22.45(10) keV | 2010 | 1.3(2) s | β− | 80Ge | 3− | |||||||||||||
| β−, n? | 79Ge | ||||||||||||||||||
| IT | 80Ga | ||||||||||||||||||
| 81Ga | 31 | 50 | 80.9381338(35) | 1976 | 1.217(5) s | β− (87.5%) | 81mGe | 5/2− | |||||||||||
| β−, n (12.5%) | 80Ge | ||||||||||||||||||
| 82Ga | 31 | 51 | 81.9431765(26) | 1976 | 600(2) ms | β− (78.8%) | 82Ge | 2− | |||||||||||
| β−, n (21.2%) | 81Ge | ||||||||||||||||||
| β−, 2n? | 80Ge | ||||||||||||||||||
| 82mGa | 140.7(3) keV | 2009 | 93.5(67) ns | IT | 82Ga | (4−) | |||||||||||||
| 83Ga | 31 | 52 | 82.9471203(28) | 1976 | 310.0(7) ms | β−, n (85%) | 82Ge | 5/2−# | |||||||||||
| β− (15%) | 83Ge | ||||||||||||||||||
| β−, 2n? | 81Ge | ||||||||||||||||||
| 84Ga | 31 | 53 | 83.952663(32) | 1991 | 97.6(12) ms | β− (55%) | 84Ge | 0−# | |||||||||||
| β−, n (43%) | 83Ge | ||||||||||||||||||
| β−, 2n (1.6%) | 82Ge | ||||||||||||||||||
| 85Ga | 31 | 54 | 84.957333(40) | 1997 | 95.3(10) ms | β−, n (77%) | 84Ge | (5/2−) | |||||||||||
| β− (22%) | 85Ge | ||||||||||||||||||
| β−, 2n (1.3%) | 83Ge | ||||||||||||||||||
| 86Ga | 31 | 55 | 85.96376(43)# | 1997 | 49(2) ms | β−, n (69%) | 85Ge | ||||||||||||
| β−, 2n (16.2%) | 84Ge | ||||||||||||||||||
| β− (15%) | 86Ge | ||||||||||||||||||
| 87Ga | 31 | 56 | 86.96901(54)# | 2010 | 29(4) ms | β−, n (81%) | 86Ge | 5/2−# | |||||||||||
| β−, 2n (10.2%) | 85Ge | ||||||||||||||||||
| β− (9%) | 87Ge | ||||||||||||||||||
| 88Ga[8] | 31 | 57 | 87.97596(54)# | 2024 | β−? | 88Ge | |||||||||||||
| β−, n? | 87Ge | ||||||||||||||||||
| 89Ga[8] | 31 | 58 | 2024 | ||||||||||||||||
| 90Ga[9] | 31 | 59 | 2026 | ||||||||||||||||
| This table header & footer: | |||||||||||||||||||
- mGa – Excited nuclear isomer.
- ( ) – Uncertainty (1σ) 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).
- Modes of decay:
EC: Electron capture IT: Isomeric transition n: Neutron emission p: Proton emission - Bold symbol as daughter – Daughter product is stable.
- ( ) spin value – Indicates spin with weak assignment arguments.
- # – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).
- Medical radioisotope used in imaging
- Half-life not measured
- Order of ground state and isomer is uncertain.
Gallium-67
Gallium-67 (67
Ga), the longest-lived radioactive isotope of gallium with a half-life of 3.2617 days, decays by electron capture with gamma emission to stable zinc-67. It is a radiopharmaceutical used in gallium scans (as is gallium-68). This isotope is imaged by a gamma camera.
It is usually used as the free ion, Ga3+.
Gallium-68
Gallium-68 (68
Ga) is a positron emitter with a half-life of 67.84 minutes, decaying to stable zinc-68. It is used as a radiopharmaceutical, generated in situ from the electron capture of germanium-68 (half-life 271.05 days) owing to its short half-life. The isotope, where a cyclotron is available, can be made in greater quantities by proton bombardment of 68Zn.[10][11] This positron-emitting isotope can be imaged efficiently by PET scan: see gallium scan. Gallium-68 is normally used as a radioactive label for a ligand which binds to certain tissues, such as DOTATOC and DOTATATE,[12] which are somatostatin analogues useful for imaging neuroendocrine tumors, which gives it a different tissue uptake specificity from the free ion gallium-67 is usually used as. Such scans are useful in locating neuroendocrine tumors and pancreatic cancer.[13] Thus, octreotide scanning for NET tumors (using indium-111) is being increasingly replaced by gallium-68 DOTATOC scan.[14]
See also
Daughter products other than gallium