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Sulfur Isotopic Reference
δ34S Values of Sulfur Isotopic Reference Materials
Description |
NIST RM # |
Material |
Nominal Unit Size |
δ34SVCDT |
Footnote |
Ref |
IAEA-S-1 |
8554 |
silver sulfide |
0.5 g |
–0.3 ‰ |
* |
11 |
IAEA-S-2 |
8555 |
silver sulfide |
0.5 g |
+22.67 ‰ |
|
12 |
IAEA-S-3 |
|
silver sulfide |
0.5 g |
–32.55 ‰ |
|
12 |
IAEA-S-4-Soufre de Lacq |
8553 |
elemental sulfur |
0.5 g |
+16.90 ‰ |
|
10 |
IAEA-SO-5 |
|
barium sulfate |
0.5 g |
+0.49 ‰ |
|
12 |
IAEA-SO-6 |
|
barium sulfate |
0.5 g |
–34.05 ‰ |
|
12 |
NBS 123 |
8556 |
sphalerite |
0.5 g |
+17.44 ‰ |
|
13 |
NBS 127 |
8557 |
barium sulfate |
0.5 g |
+21.1 ‰ |
|
12 |
* Exact value defining the delta scale
Recommendation on the Reporting of δ34S Measurements
To eliminate possible confusion in the reporting of relative sulfur isotope-amount ratio data, in 1995 at the 38th IUPAC General Assembly in Guildford, U.K., in agreement with an IAEA Consultants’ Meeting, the Commission recommended that δ34S measurements of all sulfur-bearing materials be expressed on the VCDT scale, defined by assigning a δ34S value of –0.3 ‰ exactly (relative to VCDT) to the silver sulfide reference material IAEA‑S‑1. This recommendation derives from the determination by Beaudoin et al. (ref. 24) that the Cañon Diablo meteorite, CDT, is isotopically inhomogeneous, having a range of 0.4 ‰.
Reporting of δ34S measurements relative to CDT should be discontinued.
The full recommendation appears in:
Reporting of Relative Sulfur Isotope-Ratio Data, Krouse, H. R., and Coplen, T. B., Pure Appl. Chem., 69, 293-295 (1997). [full text - pdf 163 KB] {S Isotopic Reporting Guidelines.pdf }
References
10. Qi, H.P., and Coplen, Tyler B., Evaluation of the 34S/32S ratio of Soufre de Lacq elemental sulfur isotopic reference material by continuous flow isotope-ratio mass spectrometry, Chem. Geol., 199, 183-187 (2003).
11. Robinson, B.W., Sulphur isotope standards, in Reference and intercomparison materials for stable isotopes of light elements, Vienna, International Atomic Energy Agency, IAEA-TECDOC-825, 39-45 (1995).
12. Coplen, T.B., Hopple, J.A., Böhlke, J.K., Peiser, H.S., Rieder, S.E., Krouse, H.R., Rosman, K.J.R., Ding, T., Vocke, Jr., R.D., Révész, K.M., Lamberty, A., Taylor, P., and De Bièvre, P., Compilation of minimum and maximum isotope ratios of selected elements in naturally occurring terrestrial materials and reagents, U.S. Geological Survey Water-Resources Investigations Report 01-4222, 98 p (2001).
13. Zhang, Q.L. (Chang, T.L.) and Ding, T., 1989, Analysis of the reference material NBS‑123 and the atomic weight of sulfur, Chinese Sci. Bull., 34, 1086-1089 (1989).
24. Beaudoin, G., Taylor, B. E., Rumble, III, D., and Thiemens, M., Geochim. Cosmochim. Acta, 58,4253-4255 (1994).
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