A novel ion chromatography system for Earth, Ocean, and Environmental Science

该提案要求为一种新型的高度灵活的离子色谱系统提供资金，该系统是在使用质谱法测量同位素比率之前分离单个元素所必需的。这种类型的高通量和高质量的离子色谱系统是必不可少的几个既定的和早期的职业研究（ECR）计划在SEOS。例如，申请人研究计划的一个首要主题是了解在许多时间尺度上对海洋组成的控制。目前，人为CO2排放对海洋化学产生了巨大的影响，导致生物生产力的扰动，酸化，脱氧和有害污染物的释放。为了准确预测这些变化的程度并减轻影响，我们需要更好地了解海洋化学在长期和短期尺度上的变化。跟踪海洋化学变化的一种强有力的方法是测量海水和古代沉积物中不同元素的同位素组成-测量需要通过离子色谱法进行样品纯化。例如，Ahm研究计划的一个重要组成部分是测量Ca同位素，以研究地球系统如何对CO2的长期变化做出反应。由于我们无法直接从深海中采集海水样本，因此古代沉积物的钙同位素比率为了解在整个地质时期塑造地球气候的基础过程提供了重要的见解。海洋中CO2的去除最终受控于通过碳酸盐沉积物（CaCO 3）埋藏的Ca和CO2之间的反应，连接全球钙和碳循环。因此，古碳酸盐沉积物中Ca同位素的比值（44 Ca/40 Ca）可以用来追踪海水的长期变化，并阐明短期的气候扰动。除了Ca同位素，其他非传统同位素体系的测量对申请人的研究计划也很重要。库根的研究依赖于海洋地壳中金属同位素系统的测量，如Li，Mg和K同位素，以限制地球碳循环模型并监测开发碳封存技术的有效性。Cullen的研究小组利用新的Cd同位素测量作为示踪剂，研究人类对现代海洋生物生产力和氧气减少的影响。除了申请人之外，所要求的IC系统将代表SEOS内多个研究项目的设施，建立区域分析能力，培训众多HQP，并促进利用非传统金属同位素研究地球海洋化学演变与气候系统之间联系的新研究方向。

This proposal is requesting funding for a novel and highly flexible ion chromatography (IC) system necessary for the separation of individual elements prior to measurements of isotope ratios using mass spectrometry. This type of high-throughput and high-quality ion chromatography system is essential for several established and early career research (ECR) programs within SEOS. For example, an overarching theme of the applicants' research programs is understanding the controls on the composition of the ocean over many time scales. Currently, anthropogenic CO2 emission have dramatic impacts on ocean chemistry, causing perturbations to biological productivity, acidification, de-oxygenation, and the release of harmful contaminants. To accurately predict the extent of these changes and mitigate the impacts, we need to better understand changes to ocean chemistry on both long and short time scales. A powerful method to track changes in ocean chemistry is by measuring the isotopic composition of different elements in seawater and ancient sediments - measurements that require sample purification by ion chromatography. For example, an important component of Ahm's research program is the measurement of Ca isotopes to investigate how the Earth systems responds to long-term changes in CO2. Since we cannot directly sample seawater from deep time, the Ca isotopic ratio of ancient sediments provide essential insights into the foundational processes that have shaped Earth's climate across geological time. The removal of CO2 from the ocean is ultimately controlled by the reaction between Ca and CO2 though the burial of carbonate sediments (CaCO3), linking the global calcium and carbon cycles. As a consequence, the ratio of Ca isotopes (44Ca/40Ca) in ancient carbonate sediments can be used to track both long-term changes in seawater and to elucidate short-term climate perturbations. In addition to Ca isotopes, the measurements of other non-traditional isotope system are also important to the applicants research programs. Coogan's research rely on measurements of metal isotope systems, such as Li, Mg, and K isotopes, in the ocean crust to constrain models of Earth's carbon cycle and to monitor the efficacy of developing carbon sequestration techniques. Cullen's research group utilize novel Cd isotope measurements as tracers to investigate the human-driven impacts on biological productivity and the decrease of oxygen in the modern ocean. In addition to the applicants, the requested IC system will represent a facility for multiple research programs within SEOS, build regional analytical capacity, train numerous HQP, and facilitate new research directions which exploit non-traditional metal isotopes to study the links between the evolution of Earth's ocean chemistry and climate system.