Acquisition of a Gas Chromatography-Inductively Coupled Plasma Mass Spectrometry System for Interdisciplinary Environmental and Health Sciences Research at Dartmouth College

达特茅斯学院的冯夏红博士、卡罗尔·福尔特博士和斯特凡·斯图鲁普博士获得了一笔赠款，用于购买气相色谱-电感耦合等离子体质谱仪（GC-ICPMS）系统。 该仪器的独特之处在于它提供了GC和ICPMS之间的接口。 这使得可以同时测量含无机和有机金属化合物的化学形态和同位素比。 例如，可以测定水或生物样品中无机汞和甲基汞的201 Hg/202 Hg比率。 这种分析能力为涉及挥发性金属化合物的创新观察和实验提供了各种机会，在环境和健康科学中具有重要应用。 大多数有机金属化合物的毒性明显高于相应的无机形式。因此，在环境和生物医学样品中进行特异性测定的重要性得到了广泛的重视。 该仪器将安装在达特茅斯微量元素分析核心设施（TEA Core），加入现有的高分辨率ICPMS和离子色谱（IC）系统。达特茅斯TEA Core为大量从事环境和健康科学跨学科研究的PI和学生提供服务。 新的文书将从三个方面促进我们的研究活动。 首先，它提供了新的分析能力，如汞的形态和同位素分析和硒硒蛋白的分离。 其次，它提高了一些元素测量的质量（例如，稀土元素）。 最后，它将分担我们的HR-ICPMS的分析负荷，以便技术开发工作（例如，作为物种形成）可以使用额外的机器时间来进行。 该文书促成的一个新项目是研究水生食物网中重金属，特别是汞的生物放大作用。 将比较20多个不同食物网结构的湖泊的浮游生物和鱼类组织中的甲基汞。 定量估计的影响浮游动物的种类，大小和相对丰度的积累有毒汞在鱼类从每个湖泊将用于构建一个预测模型，汞营养转移湖泊。 汞的稳定同位素的实验室实验将被用来开发在自然系统中发现的低水平汞的营养转移的机制模型。其他新的和现有的项目，将受益于这一设备包括人类健康的影响，接触有毒元素，有毒金属与细胞蛋白质的相互作用，污染物通过流域传输的机制，以及重建地球的化学和气候历史。通过成为达特茅斯的TEA核心的一部分，新的GC-ICPMS将为新兴技术领域的研究生和本科生教育提供更多的机会。 TEA核心是达特茅斯内许多部门的专家进行跨学科研究和科学交流的主要焦点。 达特茅斯的TEA核心是开放的学生研究，从一年级的本科生到博士。学生 18名研究生/博士后和15名本科生使用了该设施的仪器。 该实验室也被用于达特茅斯一些班级的课堂教学，包括本科水平的环境地质学，研究生水平的流域水文化学和分析化学和仪器分析。

A grant has been awarded to Drs. Xiahong Feng, Carol Folt and Stefan Sturup at Dartmouth College to purchase a Gas Chromatography-Inductively Coupled Plasma Mass Spectrometry (GC-ICPMS) system. The unique feature of this instrument is that it provides an interface between a GC and an ICPMS. This makes it possible to simultaneously measure chemical speciation and isotope ratios of inorganic and organic metal containing compounds. For example, one can determine 201Hg/202Hg ratios in inorganic mercury and methylmercury of water or biological samples. Such analytical power offers a variety of opportunities for innovative observations and experiments, involving volatile metal compounds, with important applications in environmental and health sciences. Most organometallic compounds are significantly more toxic than the corresponding inorganic forms. Therefore, the importance of specific determination in environmental and biomedical samples is widely appreciated. This instrument will be installed at the Dartmouth Trace Element Analysis Core Facility (TEA Core), joining an existing High Resolution-ICPMS and an ion chromatography (IC) system.The Dartmouth TEA Core serves a large number of PIs and students doing interdisciplinary research in environmental and health sciences. The new instrument will promote our research activities in three ways. First, it provides new analytical capabilities, such as mercury speciation and isotope analysis and isolation of Se from selenoproteins. Second, it improves the quality of some elemental measurements (e.g., rare earth elements). Finally, it will share the analytical load of our HR-ICPMS, so that technical development work (e.g., As speciation) can be carried out using additional machine time. A new project enabled by this instrument is a study of the biomagnification of heavy metals, especially mercury, in aquatic food webs. Methylmercury in the tissue of plankton and fish from more than 20 lakes with different food web structures will be compared. Quantitative estimates of the influence of zooplankton species, size and relative abundance on the buildup of toxic mercury in fish from each lake will used construct a predictive model for mercury trophic transfer across lakes. Laboratory experiments with stable isotopes of mercury will be used to develop mechanistic models for trophic transfer at the low levels of mercury found in natural systems. Other new and existing projects that will benefit from this equipment include human health effects of exposure to toxic elements, interaction of toxic metal with cellular proteins, mechanisms of contaminant transport through watersheds, and reconstructions of chemical and climatic history of the earth.By becoming a part of Dartmouth's TEA Core, the new GC-ICPMS will offer expanded opportunities for graduate and undergraduate education in the area of emerging technology. The TEA core is served as major foci for interdisciplinary research and scientific communication among experts in many departments within Dartmouth. Dartmouth's TEA core is open for student research from first year undergraduates to Ph.D. students. Eighteen graduate students/postdocs and 15 undergraduate students have used the instruments of the facility. The lab has also been used for classroom education in a few Dartmouth classes, including undergraduate level Environmental Geology, and graduate level Watershed Hydrochemistry and Analytical Chemistry and Instrumental Analysis.