MRI: Acquisition of Light Stable Isotope Mass Spectrometers for Research and Teaching in Geochemistry, Paleobiology, and Cosmochemistry

这个奖项是根据2009年《美国复苏和再投资法案》(公法111-5)资助的。这项提案寻求资金，用于购买两台轻稳定同位素质谱仪。这些仪器将被并入芝加哥大学新装修的稳定同位素地球化学实验室。目前该设施中最新的IRMS是已有20年历史的Delta E，不能安装在连续流动操作中。该方案寻求一种Thermo Delta V Plus IRMS，配置为具有各种引入接口(EA、TCEA、GasBENCH II)的连续流动。这将使测定大量的H、C、N、O和S同位素成为可能。此外，还需要一台用于二氧化碳、一氧化碳和硫同位素研究的MAT 253 IRMS。IRMS将被用来了解海洋磷的循环和生物地球化学。河流、河口和海洋系统的无机磷氧同位素组成不同。将使用同位素测量来跟踪淡水和沿海系统中的磷循环。细菌和古菌的PI循环将从不平衡测量中推断出来。将在海洋剖面中测量同位素不平衡，以更好地了解OM周转。这些测量需要具有逆流配置的TCEA。硫等电势将被用来理解非质量依赖的光化学和古(大气)硫循环。二氧化硫的实验将在氧气/无臭氧大气中的一定范围的紫外线照射下进行。将进行补充氧同位素测量，以加强对太古宙大气中氧分压的限制。青藏高原的应变将从地壳俯冲、地壳增厚、地幔岩石圈去除和海拔高度等方面进行分析。光稳定同位素古高度法会是分析方法吗？利用地形降水中氧和氢的强烈分馏效应。块状同位素测温法将被用来将古温度估计提高到±2°C以内，IRMS分析将被用来阐明海绵新陈代谢及其对缺乏营养的珊瑚礁系统中营养循环的影响。最近在海绵共生体中发现了诊断基因转录本，表明相关细菌的固氮作用。一氧化碳代谢在早期地球S的历史中可能是重要的。PI和合作者将研究厌氧碳营养微生物生长过程中的碳同位素分馏。将开发一种改进的进样回路系统，允许更小的样本量(S)并最终提高精密度。PI打算进行与少量碳和氧同位素有关的计算，以推断CO的形成温度。这些仪器将并入现有的加州大学同位素实验室，并将为多个部门提供支持。此次收购将代表中西部地区唯一的同位素测量能力(并提供内部校准的可能性)。稳定同位素将在本科和研究生水平的四门新课程或修订课程中使用。该实验室还将支持一项导师计划，以培训来自南芝加哥贫困地区的高中教师。同位素测量将被纳入四门新的或修订的课程。还有70多名研究生和约70名博士后也将受益。PI将负责两个购置的IRMS系统的整体操作和维护。将聘请一名全职技术人员管理实验室的日常使用和成本回收。薪酬将用于支付剩余的工资和消耗品。有足够的空间容纳新的IRMS系统，包括适当的功率、温度、冷藏和湿度要求。有氟化和真空生产线可供选择。样本优先顺序将是透明的，并向外部用户发布。因此，除了购买设备外，这笔赠款还将在芝加哥大学获得一个新的招聘职位。

0923831Colman "This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5)." This proposal seeks funding for acquisition of two light stable isotope mass spectrometers. These instruments will be incorporated into the newly renovated stable isotope geochemistry lab at the University of Chicago. The "newest" IRMS currently in the facility is a 20 year old Delta E which cannot be fitted for continuous flow operation. The proposal seeks a Thermo Delta V Plus IRMS configured for continuous flow with various introduction interfaces (EA, TCEA, GasBench II). This will allow determination of bulk H, C, N, O and S isotopes. Additionally, a MAT 253 IRMS for carbon dioxide, carbon monoxide, and sulfur isotopologue studies is requested. The IRMS will be used to understand the marine phosphorous cycle and biogeochemistry. The inorganic phosphorous oxygen isotope composition differs among riverine, estuarine and marine systems. Isotopic measurements will be used to track P cycling in freshwaters and coastal systems. Pi cycling by bacteria and archaea will be inferred from disequilibrium measurements. Isotopic disequilibria will be measured in oceanic profiles to better understand OM turnover. These measurements require the TCEA with reverse-flow configuration. Sulfur isopotologues will be used to understand non-mass-dependent photochemical and paleo- (atmospheric) sulfur cycling. Experiments will be conducted with sulfur dioxide under a range of uv irradiation in oxygen/ozone-free atmospheres. Complementary oxygen isotopes measurements will be made in order to tighten constraints on oxygen partial pressures in the Archean atmosphere. Strain across the Tibetan plateau will be analyzed in terms of crustal subduction, crustal thickening, mantle lithosphere removal, and elevation. Light stable isotope paleoaltimetry will be the analytical method ? using the strong fractionation effects seen in oxygen and hydrogen in orographic precipitation. Clumped isotope thermometry will be used to refine paleotemperature estimates to within ±2 °C. IRMS analysis will be used to elucidate sponge metabolism and its impact on nutrient cycling in nutrient-poor reef systems. Diagnostic gene transcripts have recently been identified in sponge symbionts implicating nitrogen fixation in associated bacteria. CO metabolism was likely significant in early Earth?s history. The PI and collaborators will study carbon isotopic fractionation during anaerobic carboxydotrophic microbial growth. A modified injection loop system will be developed allowing smaller sample size(s) and ultimately increased precision. The PI intends to perform calculations relating minor carbon and oxygen isotopologues to infer CO temperature formation. The instruments will be incorporated into the existing UC isotope laboratory and will support multiple departments. The acquisition will represent the only isotopologue measurement capability in the Midwest (and offer inter-calibration possibilities). Stable isotopes will be used in four new or revised courses at the undergraduate and graduate level. The laboratory will also support a mentorship program to train high school teachers from disadvantaged areas of South Chicago. Isotope measurements will be incorporated into four new or revised courses. There are over 70 graduate students and ~70 post-docs who would also benefit. The PI will be responsible for the overall operation and maintenance of both acquired IRMS systems. A full-time technician will be hired to manage day-to-day laboratory use and cost recovery. Remuneration will be used to cover remaining salary and consumables. Space is available to house the new IRMS systems including proper power, temperature, chilling and humidity requirements. Fluorination and vacuum lines are available. Sample prioritization will be transparent and published for outside users. This grant will thus lead to a new hire position at the University of Chicago in addition to equipment purchase.***