Measuring triple oxygen (16O, 17O and 18O) and carbon (12C, 13C) isotopes in small samples of carbon dioxide by laser spectroscopy

我打算在哈佛大学花5个月的时间开发和学习一种新的分析方法，用于使用中红外光谱法测量碳酸盐矿物产生的CO2小样品中的三重氧（16 O，17 O，18 O）和碳（12 C，13 C）同位素。该开发将与哈佛环境中心的丹尼尔施拉格教授（见支持信）和Aerodyne Research合作进行，Aerodyne Research是一家专门从事光谱学的私营公司，位于马萨诸塞州的比尔里卡，距离波士顿西北仅20英里。该方法将允许同时分析18 O/16 O，13 C/12 C，和17 O/16 O在CO2气体的小样品相当于微克量的碳酸钙，没有光谱干扰。激光光谱法提供了一个明显的优势，传统的同位素比质谱法（IRMS）的同位素比测量CO2，因为质量45的同量异位素干扰排除了直接测量17 O/16 O的IRMS。这种新方法将为测量迄今难以用IRMS测量的CO2和碳酸盐矿物中的17 O/16 O开辟新的研究途径。这项合作将导致一项为剑桥大学戈德温实验室购置类似系统的提议，以使该分析设施保持在稳定同位素地球化学创新技术的最前沿。

I propose to spend 5 months at Harvard University developing and learning a new analytical method for measuring triple oxygen (16O, 17O, 18O) and carbon (12C, 13C) isotopes in small samples of CO2 produced from carbonate minerals using mid-infrared spectroscopy. The development will be conducted collaboratively with Prof. Daniel Schrag at the Harvard Center for the Environment (see letter of support) and Aerodyne Research, a private-sector company specializing in spectroscopy located in Billerica, Massachusetts, only 20 miles northwest of Boston. The method will permit the simultaneous analysis of 18O/16O, 13C/12C, and 17O/16O in CO2 in small samples of CO2 gas equivalent to microgram quantities of calcium carbonate with no spectral interferences. Laser spectroscopy offers a distinct advantage over conventional isotope ratio mass spectrometry (IRMS) for the measurement of isotopic ratios in CO2 because isobaric interferences on mass 45 precludes the direct measurement of 17O/16O by IRMS. This new approach will open new avenues of research for measuring 17O/16O in CO2 and carbonate minerals that has been hitherto difficult to measure by IRMS. The collaboration will lead to a proposal to acquire a similar system for the Godwin Laboratory at the University of Cambridge to keep the analytical facility at the forefront of innovative technology for stable isotope geochemistry.