Acquisition of Experimental Gas Source Mass Spectrometer for Stable Isotope Geochemistry

0220066Eiler这笔赠款为Thermo-Finnigan委托的实验气源同位素比质谱仪提供部分支持。该仪器将提供常规分析能力，以支持我们在固体地球和大气还原气体氢同位素地球化学方面的现有计划。此外(更重要的是)，它将是第一次建立一个实验收集系统，旨在同时测量常见同位素(例如，在传统的二氧化碳质谱学中测量的12C16O16O、13C16O16O和12C18O16O)以及含有两个或更多稀有同位素的非常稀有的同位素(例如，12C18O18O、13C18O16O和13C18O18O)的相对丰度。这些物种具有不同寻常的热力学性质，这表明它们可以用来开发分子内地质温度计；我们还预计，它们在自然界中的分布受到非平衡同位素分馏的影响，例如代谢、光化学反应和质量传输的结果。这些非常罕见的同位素异构体的自然地球化学还未被探索，有望为我们对常见分子气体(例如，N2、O2、CO、CO2、N2O)的自然循环的理解增加新的维度--所有这些都将使用该仪器进行分析。*

0220066EilerThis grant provides partial support for an experimental gas source isotope ratio mass spectrometer commissioned from Thermo-Finnigan. This instrument will provide routine analytical capabilities needed to support our existing programs in the hydrogen isotope geochemistry of the solid earth and atmospheric reduced gases. Furthermore (and more importantly), it will be the first ever built with an experimental collection system designed to simultaneously measure relative abundances of common isotopomers (e.g., 12C16O16O, 13C16O16O and 12C18O16O measured in conventional mass spectrometry of CO2) and very rare isotopomers containing two or more rare isotopes (e.g., 12C18O18O, 13C18O16O and 13C18O18O). These species have unusual thermodynamic properties that suggest they can be used to develop intramolecular geothermometers; we also anticipate that their distribution in nature is influenced by non-equilibrium isotope fractionations, such as result from metabolisms, photochemical reactions, and mass transport. The natural geochemistry of these very rare isotopomers is unexplored and promises to add new dimensions to our understanding of the natural cycles of common molecular gases (e.g., N2, O2, CO, CO2, N2O - all of which will be analyzable using this instrument.***