Collaborative Research: Improving and calibrating a Tunable Infrared Laser Direct Absorption Spectroscopy (TILDAS) system for clumped isotope analysis of CO2

合作研究：改进和校准用于 CO2 聚集同位素分析的可调谐红外激光直接吸收光谱 (TILDAS) 系统

• 批准号: 1933122
• 负责人: David Dettman
• 金额: $ 44.93万
• 依托单位: University of Arizona
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-03-15 至 2022-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1933122&HistoricalAwards=false
• 关键词: Collaborative; Research; Improving; calibrating; Tunable

The study of “clumped-isotopes” concerns the tendency of heavy isotopes to “clump” into bonds with each other rather than with light isotopes in natural materials, a tendency that is temperature dependent. The co-occurrence of two rare and more massive isotopes of carbon and oxygen clumped in CO2 holds information on the temperature of the most recent chemical reactions involving these molecules. Clumped-isotope geochemistry has been applied to a wide range of subjects – from constraining atmospheric CO2 budgets to the temperature histories of meteorites. Measurements of clumping in CO2 have enabled new advances in reconstructing hydrothermal systems, climate history, paleoelevation, and the cooling history of the upper crust. The primary reason that this methodology is not more widely practiced is the difficulty of the measurement. This award will deliver a new laser-based instrument for measurement of clumped isotopes in carbonates that is much faster, cheaper, and requires less sample material than existing mass spectrometer systems. This new instrument will completely alter the landscape for clumped isotope research, making it a commonplace analysis. Such a system would be adopted quickly by laboratories around the world for application to geologic, oceanographic, biologic, and atmospheric samples, leading to new research possibilities in many scientific disciplines. This project also expands training and educational opportunities in this unusual sub-discipline of geochemistry. This project will support a postdoctoral researcher, strengthen international collaborations, and disseminate results through a conference session on laser methods. The project will also integrate research and education, broaden the participation of underrepresented groups, and broadly disseminate results by supporting a STEM Futures Fellowship research experience for undergraduates who identify with historically underrepresented groups in geoscience.This project builds on our previous funded work to develop a working laser-based (Tunable Infrared Laser Direct Absorption Spectroscopy - TILDAS) instrument for the rapid and precise measurement of clumped isotopologues of CO2 (e.g., 13C18O16O). The basic instrument has been constructed, but additional improvements in stability and development of practical sample processing are needed to produce an instrument that can be used widely in the scientific community. This laser-based measurement has major advantages over the currently used mass spectrometry approach in that it is much faster, taking only 20 minutes of analysis to achieve the required precision. Small sample size (comparable to the smallest mass spectrometer systems, and with the potential for further reductions) and a major increase in through-put will allow geochemists to extract previously unobtainable detailed temperature information from finely layered archives such as shell, fish otoliths, speleothems, soil carbonates, tufas and travertines. Fine sampling will also allow researchers to more effectively dissect diagenetic histories in carbonates, address questions related to solid-state reordering, study zoned fracture-filling cements precipitated in the sub-surface, and study kinetic and vital effects.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

对“集结 - 对体”的研究涉及重量同位素将“块”成键成键而不是天然材料中的轻质同位素的趋势，这种趋势取决于温度。二氧化碳中的两个稀有和更大的同位素的同位素共发生，凝聚在二氧化碳中的同位素含有有关这些分子的最新化学反应温度的信息。结块 - 同位素地球化学已应用于广泛的受试者 - 从限制大气二氧化碳预算到陨石的温度历史。二氧化碳聚类的测量结果使得在重建水热系统，气候历史，古平均和上皮的冷却历史方面取得了新的进步。该方法不广泛实践的主要原因是测量的困难。该奖项将提供一种新的基于激光的仪器，用于测量碳酸盐群中的聚类同位素，比现有的质谱仪系统更快，更便宜，并且所需的样品材料更少。该新仪器将彻底改变聚类同位素研究的景观，使其成为普遍的分析。这样的系统将被世界各地的实验室迅速采用，以应用于地质，海洋学，生物学和大气样本，从而在许多科学学科中产生新的研究可能性。该项目还扩大了这种不寻常的地球化学子学分中的培训和教育机会。该项目将支持博士后研究人员，更强大的国际合作，并通过激光方法会议传播结果。 The project will also integrate research and education, broaden the participation of underrepresented groups, and broadly disseminate results by supporting a STEM Futures Fellowship research experience for undergraduates who identify with historically underrepresented groups in geoscience.This project builds on our previous foundation work to develop a working laser-based (Tunable Infrared Laser Direct Absorption Spectroscopy - TILDAS) instrument for the rapid and precise measurement of CO2的聚类同位素学（例如13C18O16O）。已经构建了基本仪器，但是需要进一步改进稳定性和实际样品处理的开发来生产可以在科学界广泛使用的工具。这种基于激光的测量比当前使用的质谱法具有很大的优势，因为它的速度要快得多，只需进行20分钟的分析即可达到所需的精度。小样本量（与最小的质谱仪系统相当，并且具有进一步降低的潜力）和贯穿整个过程的重大增加将使地球化学主义者能够从诸如壳，鱼耳石，脾脏，土壤碳酸盐，碳酸盐，碳酸盐，碳酸盐，tufas和陶瓷线中提取以前无法获得的详细温度信息。精细的采样还可以使研究人员更有效地剖析碳酸盐中的电历史，解决与固态重新排序相关的问题，研究地下划分裂缝填充水泥精度，并研究动力学和生命作用。该奖项反映了NSF的法定任务，并通过使用基金会的知识分子优点和更广泛的影响审查标准来评估被认为是宝贵的支持。