Carbonate clumped isotope, quantified by Δ₄₇ value, has wide application potential in Earth science. A recently proposed carbonate standardisation scheme based on community-available reference materials (i.e., ETH-1–4) has proven to improve interlaboratory comparability in Δ₄₇ measurement. However, the shortage of these reference materials may be problematic in future; therefore, developing traceable and supplementary in-house reference materials may become necessary, especially when supplies run out. Here, we describe a method of producing synthetic witherite carbonates with variable bulk isotopic compositions and clumped isotope ordering states, for which Δ₄₇ values were determined together with ETH carbonate reference materials. Results indicate that the witherite carbonates allow effective corrections for instrumental linearity and scale variations, improving long-term reproducibility. Additionally, by normalising witherite Δ₄₇ values to agreed ETH carbonate values on the Intercarb-Carbon Dioxide Equilibrium Scale, the witherite reference materials can be used to determine Δ₄₇ values without using equilibrated gases and reduce the consumption of ETH carbonates.

中文翻译：

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用于标准化簇同位素 (Δ47) 测量的合成毒重石

_通过Δ47值量化的碳酸盐簇同位素在地球科学中具有广泛的应用潜力。最近提出的基于社区可用参考材料（即 ETH-1-4）的碳酸盐标准化方案已被证明可以提高 Δ ₄₇测量的实验室间可比性。然而，这些参考资料的短缺可能会成为未来的问题；因此，可能有必要开发可追溯和补充的内部参考材料，特别是当供应耗尽时。在这里，我们描述了一种生产具有可变本体同位素组成和团块同位素有序状态的合成毒重石碳酸盐的方法，其中 Δ ₄₇值与 ETH 碳酸盐参考材料一起确定。结果表明，毒重石碳酸盐可以有效校正仪器线性和尺度变化，从而提高长期再现性。此外，通过将毒重石 Δ ₄₇值标准化为 Intercarb-二氧化碳平衡标度上商定的 ETH 碳酸盐值，可以使用毒重石标准物质来确定 Δ ₄₇值，而无需使用平衡气体，并减少 ETH 碳酸盐的消耗。