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    Sulfur Isotope Materials

    Isotopic delta measurements of sulfur are made relative to Vienna Cañon Diablo troilite (VCDT). Traditional measurements gases are SO2 and SF6.


    δ(34/32S) Values of Reference Materials

    Name NIST RM Material δVCDT(34/32S)
    VCDTn/a 0 ‰
    IAEA-S-18554Ag2S-0.3 ‰ *
    IAEA-S-28555Ag2S+22.62(16) ‰
    IAEA-S-3Ag2S-32.49(16) ‰
    IAEA-S-48553elemental S+16.90(12) ‰
    IAEA-SO-5BaSO4+0.49(11) ‰
    IAEA-SO-6BaSO4-34.05(8) ‰
    NBS 1278557BaSO4+21.12(22) ‰
    USGS42human hair (Tibetan)+7.84(25) ‰
    USGS43human hair (Indian)+10.46(22) ‰
    Name NIST RM Material δVCDT(34/32S)

    Footnotes      Back to Top
    * Exact value defining the δ(34/32S) VCDT scale.
    ** See the Assessment of international reference materials for isotope-ratio analysis for more details.
    Values in parenthesis are expanded (k = 2) uncertainties applicable to the last digits. The values listed in this table are compilation and are not necessarily CIAAW recommendations.

    Citation

    W.A. Brand et al
    Assessment of international reference materials for isotope-ratio analysis Pure and Applied Chemistry 86, 425-467 (2014)

    CIAAW recommends that δ(34/32S) measurements of all sulfur-bearing materials be expressed relative to VCDT. The VCDT scale is defined by assigning a δ(34/32S) value of −0.3 ‰ exactly to the silver sulfide reference material IAEA-S-1.
    The full recommendation appears in Reporting of Relative Sulfur Isotope-Ratio Data by H.R. Krouse and T.B. Coplen, Pure Appl. Chem. 69 293-295 (1997).