Acquisition and Development of Two ICP Instruments: Continuous Ice Core Elemental Analyses and Other Environmental Applications

OPP-0216552麦康奈尔沙漠研究所(DRI)的教师、科学家和学生在他们的大气、水文、地球、生态系统和人类学研究中，经常需要对微量元素和同位素进行量化。DRI公司的四极电感耦合等离子体质谱仪(ICPMS)被广泛用于此类测量，但该仪器的检测下限不足以满足许多项目的要求。因此，首席调查人员要求为两台新的国际比较方案仪器提供资金：一台芬兰MAT Element2高分辨率双聚焦电感耦合等离子体质谱仪和一台瓦里安Vista-Pro轴视电感耦合等离子体光学发射光谱仪(ICPOES)，这是重大研究仪器(MRI)计划下的一台。需要额外的资金用于仪器开发，以便将两台国际比较方案仪器纳入DRI最近开发的冰芯中的连续微量元素和同位素分析方法。NSF赞助的美国冰芯工作组明确指出，持续改进高分辨率能力是继续进行美国冰芯研究的优先要求。鉴于收集和储存冰芯的成本很高，而且它们有可能提供关于过去各种时间和空间尺度上的大气化学、大气和海洋环流以及人为污染的非常详细的信息，显然有必要采用尽可能最佳的分析程序和仪器来进行冰芯分析。美国水利部最近开发了一种新的、高效的方法，使用电感耦合等离子体质谱对冰芯上的痕量元素和化学物种进行连续、高分辨率和准确的联合记录测量。来自格陵兰岛顶峰的~135米(M)岩心上15种化学物种和元素的测量，以及使用南极洲Siple Dome岩心开发的试点数据，证明了这种新方法的潜力以及DRI的四极电感耦合等离子体质谱仪的局限性。在冰芯中，一些重要元素和同位素的浓度低于四极电感耦合等离子体质谱仪的检测下限。这个问题也阻碍了其他环境科学的应用，因为元素和同位素数据是回答关键问题的基础。虽然这项建议的一个主要目标是显著提高美国冰芯研究的水平和范围，但最先进的电感耦合等离子体质谱仪和电感耦合等离子体发射光谱仪的提供将改善和扩大DRI以及内华达州大学和社区学院系统(UCCSN)教职员工在其他领域(例如，污染气溶胶对降水的影响、地下水指纹、确定地表水中胶体物质来源、考古学中的微量元素分析)的研究能力。特别是，作为内华达州唯一能够进行专门的高分辨率元素和同位素分析的电感耦合等离子体质谱仪，收购Element2电感耦合等离子体质谱仪将吸引新的教员加入DRI和UCCSN系统(目标是增加多样性)，并改善和扩大全州研究生和本科生培训的机会。

OPP-0216552McConnellFaculty, scientists, and students of the Desert Research Institute (DRI) routinely need to quantify trace elements and isotopes in their research in atmospheric, hydrologic, earth, ecosystem, and anthropological sciences. DRI's quadrapole inductively coupled plasma mass spectrometer (ICP-MS) is widely used for such measurements, but the detection limits of this instrument are inadequate for many projects. Therefore, the Principal Investigators have requested funding for two new ICP instruments: a Finnigan MAT Element2 high-resolution, double focusing ICP-MS and a Varian Vista-Pro axially viewed inductively coupled plasma optical emission spectrometer (ICP-OES) under the Major Research Instrumentation (MRI) Program. Additional funds are requested for instrument development to incorporate the two ICP instruments into DRI's recently developed method for continuous trace element and isotope analyses in ice cores. Continual improvement of high-resolution capabilities specifically was identified by the NSF-sponsored U.S. Ice Core Working Group as a priority requirement for the continuation of U.S. ice core research. Given the high cost of collecting and storing ice cores and their potential to provide highly detailed information on past atmospheric chemistry, atmospheric and oceanic circulation, and anthropogenic pollution across a wide range of temporal and spatial scales, it is clear that the best possible analytical procedures and instrumentation for ice core analyses are warranted. DRI faculty has recently developed a novel, efficient method using ICP-MS to make continuous, high-resolution and exactly co-registered measurements of trace elements and chemical species on ice cores. Measurements of 15 chemical species and elements on a ~135 meter (M) core from Summit, Greenland, and pilot data developed using cores from Siple Dome, Antarctica, demonstrate the potential of this new approach as well as the limitations of DRI's quadrapole ICP-MS. In ice cores, the concentrations of some important elements and isotopes are below the detection limits of the quadrapole ICP-MS. This problem also hinders other environmental science applications where elemental and isotope data are fundamental to answering critical questions. While a major objective of this proposal is to significantly advance the level and scope of U.S. ice core research, the availability of a state-of-the-art ICP-MS and ICP-OES will improve and expand research capabilities for DRI and University and Community College System of Nevada (UCCSN) faculty working in other fields (e.g., impact of pollution aerosols on precipitation, groundwater fingerprinting, determination of sources of colloidal material in surface waters, trace element analysis in archeology). In particular, as the only ICP-MS in Nevada capable of dedicated, high-resolution elemental and isotopic analyses, the acquisition of the Element2 ICP-MS will attract new faculty to DRI and the UCCSN system (with a goal of increasing diversity) as well as improve and expand opportunities for graduate and undergraduate student training throughout the state.