Mann Jacqueline L, Vocke Robert D, Kelly W Robert
Inorganic Chemical Metrology Group, Analytical Chemistry Division, National Institute of Standards and Technology, 100 Bureau Drive, MS8391, Gaithersburg, MD 20899, USA.
Rapid Commun Mass Spectrom. 2009 Apr;23(8):1116-24. doi: 10.1002/rcm.3977.
Revised delta(34)S reference values with associated expanded uncertainties (95% confidence interval (C.I.)) are presented for the sulfur isotope reference materials IAEA-S-2 (22.62 +/- 0.16 per thousand) and IAEA-S-3 (-32.49 +/- 0.16 per thousand). These revised values are determined using two relative-difference measurement techniques, gas source isotope ratio mass spectrometry (GIRMS) and double-spike multi-collector thermal ionization mass spectrometry (MC-TIMS). Gas analyses have traditionally been considered the most robust for relative isotopic difference measurements of sulfur. The double-spike MC-TIMS technique provides an independent method for value-assignment validation and produces revised values that are both unbiased and more precise than previous value assignments. Unbiased delta(34)S values are required to anchor the positive and negative end members of the sulfur delta (delta) scale because they are the basis for reporting both delta(34)S values and the derived mass-independent Delta(33)S and Delta(36)S values.
给出了硫同位素参考物质国际原子能机构 - S - 2（22.62±0.16‰）和国际原子能机构 - S - 3（-32.49±0.16‰）的修订后的δ(34)S参考值以及相关的扩展不确定度（95%置信区间（C.I.））。这些修订值是使用两种相对差值测量技术确定的，即气体源同位素比值质谱法（GIRMS）和双尖峰多接收器热电离质谱法（MC - TIMS）。传统上认为气体分析对于硫的相对同位素差值测量最为可靠。双尖峰MC - TIMS技术为赋值验证提供了一种独立方法，并产生了比先前赋值更无偏差且更精确的修订值。无偏差的δ(34)S值是确定硫δ（δ）标度的正负端元所必需的，因为它们是报告δ(34)S值以及导出的与质量无关的Δ(33)S和Δ(36)S值的基础。
