MRI-R2: Acquisition of a Proton Transfer Reaction Time-of-Flight Mass Spectrometer for Atmospheric Chemistry

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。该奖项支持购买最先进的高分辨率质子转移飞行时间质谱仪（PTR-ToF-MS），该质谱仪将用于进一步了解生物挥发性有机化合物（BVOCs）的大气化学。该仪器具有比更常见的四极杆PTR-MS更好的质量分辨率的重要优势，其允许将不同元素组成的同量异位素离子分离。研究将包括测量森林的BVOC排放量，研究BVOC与大气氧化剂在臭氧形成潜力和二次有机气溶胶产生方面的反应，以及BVOC排放对不断变化的生物和气候因素的敏感性。这些研究将利用实地测量和实验室反应室实验相结合的方法。虽然以前的许多研究都着眼于BVOCs的形成，但在理解方面仍然存在重大差距。特别是，化学模型目前对大气气溶胶的有机负荷的预测不足4至8倍。据推测，这种“失踪的有机物质”包括尚未确定的BVOC前体来源于植物排放。PTR-ToF-MS将用于搜索和识别这些化合物并量化其排放。测量将在哈佛森林和哈佛环境室进行，该森林是20多年前建立的长期生态研究（LTER）场所。测量结果将在空气质量和气候强迫方面具有重要意义。此外，该仪器还将用于一个新的研究生物排放和气溶胶产生的联合体。四个新英格兰机构被提议作为区域中心的初始组成部分：阿默斯特学院，哈佛大学，波士顿学院和佛蒙特大学。该中心的一个重点将是增加本科生的研究机会。活动将包括每月小组会议，夏季和学年的研究机会，将重点放在本科生，社会活动，以加强指导和网络，以及两年一度的研究研讨会。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).This award supports acquisition of a state-of-the-art high-resolution proton-transfer time-of-flight mass spectrometer (PTR-ToF-MS) that will be used to further understanding of the atmospheric chemistry of biogenic volatile organic compounds (BVOCs). This instrument has the important advantage over the more common quadrupole PTR-MS of a much better mass resolution, which allows isobaric ions of different elemental composition to be separated. Research will include measurements of BVOC emissions from forests and study of BVOC reactions with atmospheric oxidants in the context of their ozone-forming potential and production of secondary organic aerosols as well as the susceptibility of BVOC emissions to changing biological and climatological factors. The studies will utilize a combination of field measurements and laboratory reaction chamber experiments. While many previous studies have looked at the formation of BVOCs, significant gaps in understanding still exist. In particular, chemical models currently underpredict the organic loading of atmospheric aerosols by factors of 4 to 8. It is hypothesized that this 'missing organic mass' consists of as-yet unidentified BVOC precursors originating from plant emissions. The PTR-ToF-MS will be used to search for and identify these compounds and quantify their emissions. Measurements will be made at Harvard Forest, which was established as a Long Term Ecological Research (LTER) site more than 20 years ago, and the Harvard environmental chamber.The results will be of great importance in the context of both air quality and climate forcing. In addition, the instrument will be used in the context of a new consortium for studies of biogenic emissions and production of aerosols. Four New England institutions are proposed as initial components of a regional center: Amherst College, Harvard University, Boston College, and the University of Vermont. A focus of the center will be enhanced research opportunities for undergraduates. Activities will include monthly group meetings, summer and academic-year research opportunities that will focus on undergraduate students, social activities to enhance mentoring and networking, and biennial research symposia.