Isotopes of gallium

Natural gallium (₃₁Ga) consists of a mixture of two stable isotopes: gallium-69 and gallium-71. The most commercially important radioisotopes are gallium-67 and gallium-68.

Main isotopes of gallium (₃₁Ga)

Iso­tope Decay abun­dance half-life (t1/2) mode pro­duct ^66Ga syn 9.5 h β^+ ^66Zn ^67Ga syn 3.3 d ε ^67Zn ^68Ga syn 1.2 h β^+ ^68Zn ^69Ga 60.11% stable ^70Ga syn 21 min β^− ^70Ge ε ^70Zn ^71Ga 39.89% stable ^72Ga syn 14.1 h β^− ^72Ge ^73Ga syn 4.9 h β^− ^73Ge
Standard atomic weight Ar, standard(Ga)	69.723(1)[1]

Gallium-67 (half-life 3.3 days) is a gamma-emitting isotope (the gamma emitted immediately after electron-capture) used in standard nuclear medical imaging, in procedures usually referred to as gallium scans. It is usually used as the free ion, Ga³⁺. It is the longest-lived radioisotope of gallium.

The shorter-lived gallium-68 (half-life 68 minutes) is a positron-emitting isotope generated in very small quantities from germanium-68 in gallium-68 generators or in much greater quantities by proton bombardment of ⁶⁸Zn in low-energy medical cyclotrons,[2] for use in a small minority of diagnostic PET scans. For this use, it is usually attached as a tracer to a carrier molecule, which gives the resulting radiopharmaceutical a different tissue-uptake specificity from the ionic ⁶⁷Ga radioisotope normally used in standard gallium scans.

List of isotopes

Nuclide [n 1]	Z	N	Isotopic mass (Da) [n 2][n 3]	Half-life	Decay mode [n 4]	Daughter isotope [n 5]	Spin and parity [n 6][n 7]	Natural abundance (mole fraction)
	Excitation energy							Normal proportion	Range of variation
^56Ga	31	25	55.99491(28)#		p	^55Zn	3+#
^57Ga	31	26	56.98293(28)#		p	^56Zn	1/2−#
^58Ga	31	27	57.97425(23)#		p	^57Zn	2+#
^59Ga	31	28	58.96337(18)#		p	^58Zn	3/2−#
^60Ga	31	29	59.95706(12)#	70(10) ms	β^+	^60Zn	(2+)
^61Ga	31	30	60.94945(6)	168(3) ms	β^+	^61Zn	3/2−
^62Ga	31	31	61.944175(30)	116.18(4) ms	β^+	^62Zn	0+
^63Ga	31	32	62.9392942(14)	32.4(5) s	β^+	^63Zn	(3/2−)
^64Ga	31	33	63.9368387(22)	2.627(12) min	β^+	^64Zn	0(+#)
^64mGa	42.85(8) keV			21.9(7) μs			2+
^65Ga	31	34	64.9327348(9)	15.2(2) min	β^+	^65Zn	3/2−
^66Ga	31	35	65.931589(3)	9.49(7) h	β^+	^66Zn	0+
^67Ga[n 8]	31	36	66.9282017(14)	3.2612(6) d	EC	^67Zn	3/2−
^68Ga[n 9]	31	37	67.9279801(16)	67.71(9) min	β^+	^68Zn	1+
^69Ga	31	38	68.9255736(13)	Stable			3/2−	0.60108(9)
^70Ga	31	39	69.9260220(13)	21.14(3) min	β^− (99.59)	^70Ge	1+
					EC (0.41%)	^70Zn
^71Ga	31	40	70.9247013(11)	Stable			3/2−	0.39892(9)
^72Ga	31	41	71.9263663(11)	14.095(3) h	β^−	^72Ge	3-
^72mGa	119.66(5) keV			39.68(13) ms	IT	^72Ga	(0+)
^73Ga	31	42	72.9251747(18)	4.86(3) h	β^−	^73Ge	3/2−
^74Ga	31	43	73.926946(4)	8.12(12) min	β^−	^74Ge	(3-)
^74mGa	59.571(14) keV			9.5(10) s			(0)
^75Ga	31	44	74.9265002(26)	126(2) s	β^−	^75Ge	(3/2)−
^76Ga	31	45	75.9288276(21)	32.6(6) s	β^−	^76Ge	(2+,3+)
^77Ga	31	46	76.9291543(26)	13.2(2) s	β^−	^77Ge	(3/2−)
^78Ga	31	47	77.9316082(26)	5.09(5) s	β^−	^78Ge	(3+)
^79Ga	31	48	78.93289(11)	2.847(3) s	β^− (99.911%)	^79mGe	(3/2−)#
					β^−, n (.089%)	^78Ge
^80Ga	31	49	79.93652(13)	1.697(11) s	β^− (99.11%)	^80Ge	(3)
					β^−, n (.89%)	^79Ge
^81Ga	31	50	80.93775(21)	1.217(5) s	β^− (88.11%)	^81mGe	(5/2−)
					β^−, n (11.89%)	^80Ge
^82Ga	31	51	81.94299(32)#	0.599(2) s	β^− (78.5%)	^82Ge	(1,2,3)
					β^−, n (21.5%)	^81Ge
^83Ga	31	52	82.94698(32)#	308(1) ms	β^− (60%)	^83Ge	3/2−#
					β^−, n (40%)	^82Ge
^84Ga	31	53	83.95265(43)#	0.085(10) s	β^−, n (70%)	^83Ge
					β^− (30%)	^84Ge
^85Ga	31	54	84.95700(54)#	50# ms [>300 ns]			3/2−#
^86Ga	31	55	85.96312(86)#	30# ms [>300 ns]

1. ^mGa – 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. Modes of decay:

   EC:	Electron capture
   IT:	Isomeric transition
   n:	Neutron emission
   p:	Proton emission

5. Bold symbol as daughter – Daughter product is stable.
6. ( ) spin value – Indicates spin with weak assignment arguments.
7. # – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).
8. Deexcitation gamma used in medical imaging
9. Medically useful radioisotope

• Commercially available materials may have been subjected to an undisclosed or inadvertent isotopic fractionation. Substantial deviations from the given mass and composition can occur.

Gallium-67

Radiopharmaceutical.

Gallium-68

Radiopharmaceutical.

References

1. Meija, Juris; et al. (2016). "Atomic weights of the elements 2013 (IUPAC Technical Report)". Pure and Applied Chemistry. 88 (3): 265–91. doi:10.1515/pac-2015-0305.
2. Kumlin, J; Dam, J; Langkjaer, N; Chua, C.J.; Borjian, S.; Kassaian, A; Hook, B; Zeisler, S; Schaffer, P; Helge, Thisgaard (October 2019). "Multi-Curie Production of Ga-68 on a Biomedical Cyclotron". Conference: EANM'19. Retrieved 13 December 2019.

• 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. Lay summary.
• 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.