Equipment: MRI: Track 1 Acquisition of a Stable Isotope Mass Spectrometer for Earth and Ocean Science Research

设备： MRI：轨道 1 采购用于地球和海洋科学研究的稳定同位素质谱仪

• 批准号: 2320391
• 负责人: Brian Popp
• 金额: $ 20.97万
• 依托单位: University of Hawaii
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-15 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2320391&HistoricalAwards=false
• 关键词: Equipment; MRI; Track; Acquisition; Stable

This project is jointly funded by the Division of Earth Sciences and the Established Program to Stimulate Competitive Research (EPSCoR). This Major Research Instrumentation (MRI) award supports acquisition of a state-of-the-art isotope ratio mass spectrometer to be used for earth and ocean science research. The instrument will be integrated into the existing stable isotope biogeochemistry laboratory and will replace an obsolete and increasingly unreliable mass spectrometer purchased in 1991 at the University of Hawaii at Manoa. The equipment will be used principally for isotope analyses of nitrate, nitrite and ammonium that are crucial for catalyzing new research capacity and supporting existing research strengths in biogeochemistry in Hawaii. The new isotope ratio mass spectrometer will contribute to University of Hawaii’s educational goals by training researchers at every level (e.g., professors, postdocs, students) for stable isotope analyses, though new collaborations, teaching efforts, and a “seed analysis” program as well as provide support for ongoing NSF REU programs and the UH Undergraduate Research Opportunities Program. The isotope ratio mass spectrometer will also support the research of three young faculty including two nā wāhine (women) of native Hawaiian ancestry.Nitrogen inputs into groundwater aquifers in Hawaii and other volcanic islands in the Pacific pollutes drinking water supplies. Identification of groundwater contamination pathways is critically important for island environments like Hawaii where 99% of domestic water supply is from groundwater. Submarine ground water discharge of nutrient-rich waters can contaminate nearshore environments as well as promote ecological changes in nearshore reef ecosystems. Knowing pathways of ground flow in aquifers allows assessment of how land use relates to groundwater contamination and isotope analyses of nitrate, nitrite and ammonium can be used to identify sources and fates of nitrogen contamination in groundwater and nearshore environments, which includes residential cesspools and sewage injection into groundwater. Of the 110,000 residential on-site disposal systems in use in Hawaii, the majority are cesspools that State-wide discharge ~265 million liters per day of minimally treated sewage effluent into groundwater. New State of Hawaii regulations require that all cesspools must be “upgraded, converted, or closed” by 2050. Cesspool sewage hotspots must be identified and appropriate alternatives to residential sewage disposal determined. Isotopic analyses of nitrate, nitrite and ammonium facilitated by the new equipment will support scientific studies in Hawaii and on other Pacific Islands that will address these challenges. Isotope analyses of nitrate and nitrite in seawater are fundamental measurement used to quantify nitrogen cycling in the ocean. Researchers at University of Hawaii have used 15N-labeled nitrate and nitrite to study microbial nitrification in several marine environments. Nitrification in the ocean plays a critical role in the nitrogen cycle by changing the form in which N occurs—in turn influencing the accessibility and availability of nitrogen to different groups of organisms and processes. Studies using 15N-labeled substrates provide critical information on rates of ammonia and nitrite oxidation, and when coupled with genetic analyses, reveal important insights into the ecology and regulation of these biogeochemically-important processes in all marine systems.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.

该项目由地球科学部和刺激竞争性研究的既定计划（EPSCoR）共同资助。 这项重大研究仪器（MRI）奖支持购买最先进的同位素比质谱仪，用于地球和海洋科学研究。该仪器将并入现有的稳定同位素地球化学实验室，并将取代马诺阿夏威夷大学1991年购买的一台过时的、越来越不可靠的质谱仪。该设备将主要用于硝酸盐、亚硝酸盐和铵的同位素分析，这对于促进新的研究能力和支持夏威夷地球化学的现有研究力量至关重要。新的同位素比质谱仪将有助于夏威夷大学的教育目标，培训各级研究人员（例如，通过新的合作、教学努力和“种子分析”计划，以及为正在进行的NSF REU计划和UH本科生研究机会计划提供支持，为稳定同位素分析提供支持。同位素比质谱仪还将支持三名年轻教师的研究，其中包括两名夏威夷土著血统的nwāhine（女性）。氮进入夏威夷和太平洋其他火山岛的地下蓄水层，污染了饮用水供应。对于像夏威夷这样的岛屿环境，地下水污染途径的识别至关重要，因为99%的生活用水来自地下水。富含营养物的沃茨的海底地下水排放会污染近岸环境，并促进近岸珊瑚礁生态系统的生态变化。了解含水层中地下水流的途径，可以评估土地利用与地下水污染的关系，硝酸盐、亚硝酸盐和铵的同位素分析可以用来确定地下水和近岸环境中氮污染的来源和归宿，包括住宅蓄水池和污水注入地下水。在夏威夷使用的110，000个住宅现场处理系统中，大多数是污水池，全州每天将约2.65亿升经过最低限度处理的污水排放到地下水中。新的夏威夷州法规要求，到2050年，所有的游泳池必须“升级、改造或关闭”。必须确定污水池污水热点，并确定住宅污水处理的适当替代办法。新设备有助于对硝酸盐、亚硝酸盐和铵进行同位素分析，这将支持在夏威夷和其他太平洋岛屿进行的科学研究，以应对这些挑战。海水中硝酸盐和亚硝酸盐的同位素分析是用于定量海洋中氮循环的基本测量方法。夏威夷大学的研究人员使用15 N标记的硝酸盐和亚硝酸盐来研究几种海洋环境中的微生物硝化作用。海洋中的硝化作用通过改变氮的存在形式在氮循环中起着至关重要的作用，从而影响氮对不同生物群和过程的可获得性和可用性。使用15 N标记底物的研究提供了氨和亚硝酸盐氧化速率的关键信息，当与遗传分析相结合时，揭示了对所有海洋系统中这些重要的生态地球化学过程的生态和调节的重要见解。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的知识价值和更广泛的影响审查标准进行评估来支持。