Acquisition of a Stable Isotope Ratio Mass Spectrometer System for Environmental and Paleoclimatic Research

这笔赠款支持明尼苏达大学购买稳定的同位素比质谱仪(SIRMS)，用于环境和古气候研究以及现代生态学、水文学、湖湖学和水化学。将购买一台带有在线外围设备的连续流动(CF)质谱仪，该设备可以自动准备样品并将净化气体直接引入离子源，以取代2001年退役的已有20年历史的芬兰垫子Delta E。CF-SIRMS将减少需要处理的样本大小，从而允许进行更高分辨率的样本序列研究，并增加样本吞吐量和精度。将立即受益于所要求的SIMRS能力的研究包括：1)美国大陆中部表层和地下水之间现代相互作用的研究，如湖泊栖息浮游微生物和动物遗骸的同位素组成记录所记录的那样；2)湖泊和湿地的碳平衡调查；3)通过对生物成因磷灰石化石的稳定同位素分析进行的新生代哺乳动物古饮食调查，这对于阐明已灭绝生物的古环境具有重要意义；4)在火山岩和方解石稳定同位素分析的基础上进行区域第四纪古气候调查。该仪器还将用于培训来自不同部门的博士后和研究生。为了促进跨学科工作，每两年将举办一次研讨会，教职员工和学生将在研讨会上讨论他们的研究，重点是同位素分析的作用。参加该大学REU项目的本科生将参与使用新仪器的研究。还将访问印度保留地，在那里将介绍关于食物网和水文/沉积物循环的讲座。***

0549633ItoThis grant supports acquisition of a stable isotope ratio mass spectrometer (SIRMS) for environmental and paleoclimate research as well as modern ecological studies, hydrology, limnology, and aqueous geochemistry at the University of Minnesota. A continuous flow (CF) mass spectrometer with on-line peripheral devices that prepare samples automatically and introduce the purified gases directly into the ion source will be purchased, replacing a 20-year old Finnigan MAT delta E that was decommissioned in 2001. The CF-SIRMS will reduce the size of samples needed to be processed and therefore allow higher resolution studies of sample sequences to take place and increase sample throughput and precision. Research that will immediately benefit from the capabilities of the requested SIMRS include: 1) studies of modern interactions between surface and groundwaters in the mid-continental U.S. as recorded in the isotopic composition of the remains of lacustrine dwelling planktonic microflora and fauna and related paleorecords studies with implications for understanding past climate variability in the mid-continent; 2) carbon balance investigations in lakes and wetlands; 3) investigations of Cenozoic mammalian paleodiets through stable isotopic analysis of fossil biogenic apatite with implications for elucidating the paleoenvironments of extinct organisms; and 4) regional Quaternary paleoclimate investigations based on stable isotopic analysis of speleothem calcite. The instrument will be also used to train postdocs and graduate students from a variety of departments. To foster interdisciplinary work, a seminar will be offered every two years where faculty and students will talk about their research, focusing on the role of isotope analyses. Undergraduate students participating in the university's REU program will be involved in research that uses the new instrumentation. Indian reservations will also be visited where talks on the food web and hydrologic/sediment cycle will be presented. ***