Isotopes of sulfur

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Sulfur (S) has 18 isotopes, four of which are stable: ³²S (95.02%), ³³S (0.75%), ³⁴S (4.21%), and ³⁶S (0.02%). Other than ³⁵S, the radioactive isotopes of sulfur are all short lived. ³⁵S is formed from cosmic ray spallation of ⁴⁰Ar in the atmosphere. It has a half-life of 87 days. Standard atomic mass: 32.065(5) u

When sulfide minerals are precipitated, isotopic equilibration among solids and liquid may cause small differences in the δS-34 values of co-genetic minerals. The differences between minerals can be used to estimate the temperature of equilibration. The δC-13 and δS-34 of coexisting carbonates and sulfides can be used to determine the pH and oxygen fugacity of the ore-bearing fluid during ore formation.

In most forest ecosystems, sulfate is derived mostly from the atmosphere; weathering of ore minerals and evaporites also contribute some sulfur. Sulfur with a distinctive isotopic composition has been used to identify pollution sources, and enriched sulfur has been added as a tracer in hydrologic studies. Differences in the natural abundances can also be used in systems where there is sufficient variation in the ³⁴S of ecosystem components. Rocky Mountain lakes thought to be dominated by atmospheric sources of sulfate have been found to have different δS-34 values from lakes believed to be dominated by watershed sources of sulfate.

1 Table
- 1.1 Notes
2 References
3 External links

[edit] Table

nuclide symbol	Z(p)	N(n)	isotopic mass (u)	half-life	nuclear spin	representative isotopic composition (mole fraction)	range of natural variation (mole fraction)
nuclide symbol	excitation energy			half-life	nuclear spin	representative isotopic composition (mole fraction)	range of natural variation (mole fraction)
²⁶S	16	10	26.02788(32)#	10# ms	0+
²⁷S	16	11	27.01883(22)#	15.5(15) ms	(5/2+)
²⁸S	16	12	28.00437(17)	125(10) ms	0+
²⁹S	16	13	28.99661(5)	187(4) ms	5/2+
³⁰S	16	14	29.984903(3)	1.178(5) s	0+
³¹S	16	15	30.9795547(16)	2.572(13) s	1/2+
³²S	16	16	31.97207100(15)	STABLE	0+	0.9499(26)	0.94454-0.95281
³³S	16	17	32.97145876(15)	STABLE	3/2+	0.0075(2)	0.00730-0.00793
³⁴S	16	18	33.96786690(12)	STABLE	0+	0.0425(24)	0.03976-0.04734
³⁵S	16	19	34.96903216(11)	87.51(12) d	3/2+
³⁶S	16	20	35.96708076(20)	STABLE	0+	0.0001(1)	0.00013-0.00019
³⁷S	16	21	36.97112557(21)	5.05(2) min	7/2-
³⁸S	16	22	37.971163(8)	170.3(7) min	0+
³⁹S	16	23	38.97513(5)	11.5(5) s	(3/2,5/2,7/2)-
⁴⁰S	16	24	39.97545(15)	8.8(22) s	0+
⁴¹S	16	25	40.97958(13)	1.99(5) s	(7/2-)#
⁴²S	16	26	41.98102(13)	1.013(15) s	0+
⁴³S	16	27	42.98715(22)	260(15) ms	3/2-#
^43mS	319(5) keV			480(50) ns	(7/2-)
⁴⁴S	16	28	43.99021(42)	100(1) ms	0+
⁴⁵S	16	29	44.99651(187)	68(2) ms	3/2-#
⁴⁶S	16	30	46.00075(75)#	50(8) ms	0+
⁴⁷S	16	31	47.00859(86)#	20# ms [>200 ns]	3/2-#
⁴⁸S	16	32	48.01417(97)#	10# ms [>200 ns]	0+
⁴⁹S	16	33	49.02362(102)#	<200 ns	3/2-#

[edit] Notes

The precision of the isotope abundances and atomic mass is limited through variations. The given ranges should be applicable to any normal terrestrial material.
Values marked # are not purely derived from experimental data, but at least partly from systematic trends. Spins with weak assignment arguments are enclosed in parentheses.
Uncertainties are given in concise form in parentheses after the corresponding last digits. Uncertainty values denote one standard deviation, except isotopic composition and standard atomic mass from IUPAC which use expanded uncertainties.

[edit] References

Isotope masses from Ame2003 Atomic Mass Evaluation by G. Audi, A.H. Wapstra, C. Thibault, J. Blachot and O. Bersillon in Nuclear Physics A729 (2003).
Isotopic compositions and standard atomic masses from Atomic weights of the elements. Review 2000 (IUPAC Technical Report). Pure Appl. Chem. Vol. 75, No. 6, pp. 683-800, (2003) and Atomic Weights Revised (2005).
Half-life, spin, and isomer data selected from these sources. Editing notes on this article's talk page.
- Audi, Bersillon, Blachot, Wapstra. The Nubase2003 evaluation of nuclear and decay properties, Nuc. Phys. A 729, pp. 3-128 (2003).
- National Nuclear Data Center, Brookhaven National Laboratory. Information extracted from the NuDat 2.1 database (retrieved Sept. 2005).
- David R. Lide (ed.), Norman E. Holden in CRC Handbook of Chemistry and Physics, 85th Edition, online version. CRC Press. Boca Raton, Florida (2005). Section 11, Table of the Isotopes.