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Updated: Jun 24, 2026

Preparation of Authigenic Pyrite from Methane-bearing Sediments for In Situ Sulfur Isotope Analysis Using SIMS
Published on: August 31, 2017
Revised delta34S reference values for IAEA sulfur isotope reference materials S-2 and S-3
Jacqueline L Mann1, Robert D Vocke, W Robert Kelly
1Inorganic Chemical Metrology Group, Analytical Chemistry Division, National Institute of Standards and Technology, 100 Bureau Drive, MS8391, Gaithersburg, MD 20899, USA. jmann@nist.gov
Revised sulfur isotope reference values for IAEA-S-2 and IAEA-S-3 were determined using gas source isotope ratio mass spectrometry (GIRMS) and double-spike multi-collector thermal ionization mass spectrometry (MC-TIMS). These new values offer improved precision and accuracy for sulfur delta scale anchoring.
Area of Science:
- Geochemistry
- Analytical Chemistry
- Isotope Science
Background:
- Accurate sulfur isotope reference materials are crucial for geochemical studies.
- Previous sulfur isotope reference values required refinement for enhanced precision.
Purpose of the Study:
- To provide revised delta(34)S reference values for IAEA-S-2 and IAEA-S-3.
- To validate measurement techniques for sulfur isotope analysis.
- To improve the accuracy of the sulfur delta scale.
Main Methods:
- Sulfur isotope ratio measurements using gas source isotope ratio mass spectrometry (GIRMS).
- Sulfur isotope ratio measurements using double-spike multi-collector thermal ionization mass spectrometry (MC-TIMS).
- Comparative analysis of data from both techniques for validation.
Main Results:
- Revised delta(34)S values for IAEA-S-2 (22.62 ± 0.16‰) and IAEA-S-3 (-32.49 ± 0.16‰).
- Demonstrated that double-spike MC-TIMS provides unbiased and more precise values than previous assignments.
- Confirmed GIRMS as a robust technique for relative isotopic difference measurements.
Conclusions:
- The revised reference values enhance the accuracy of the sulfur delta scale.
- Double-spike MC-TIMS offers a reliable method for validating sulfur isotope reference materials.
- Precise sulfur isotope measurements are essential for reporting delta(34)S, Delta(33)S, and Delta(36)S values.
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