Extending the Use of Proton-Transfer-Reaction Mass Spectrometer (PTR-MS) for New Measurements of Volatile Organic Compounds and Their Oxidation Products - Phase II

扩展质子转移反应质谱仪 (PTR-MS) 的使用，用于挥发性有机化合物及其氧化产物的新测量 - 第二阶段

• 批准号: 0443448
• 负责人: Allen Goldstein
• 金额: $ 54.99万
• 依托单位: University of California-Berkeley
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-02-15 至 2010-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0443448&HistoricalAwards=false
• 关键词: Extending; Use; Proton; Transfer; Reaction

This project addresses biogenic emissions of volatile organic compounds (VOC), which will be measured at the Blodgett Forest site in central California. Fast response Proton-Transfer-Reaction Mass Spectrometers (PTR-MS) will be used for real-time in-situ measurements of concentrations and fluxes of biogenic VOCs, especially terpenes. These play important roles in the chemistry of the atmosphere by contributing to the cycling of important atmospheric radicals and tropospheric ozone, and through secondary organic aerosol formation. With earlier NSF support, field measurements of vertical concentration profiles through the forest canopy revealed the presence of large amounts of previously unreported oxidation products, which were also observed in smog chamber studies. The results suggest that about half the ecosystem scale ozone flux measured at Blodgett Forest in summer is due to chemical reactions of ozone with terpenes within the forest canopy, and that the flux of terpenes leaving the forest canopy represents only a small fraction of the terpenoid compounds actually emitted, while the rest is chemically processed within the forest canopy. In the next phase of this research, the following objectives will be pursued:1. The smog chamber research will be expanded to include full photochemical oxidation experiments in collaboration with Prof. Seinfeld at Caltech in order to identify even more of the relevant oxidation products under more representative atmospheric conditions; 2. The vertical flux of terpene oxidation products out of the forest canopy will be measured using the eddy covariance method; 3. New field measurements will be performed to observe the full suite of terpene oxidation products with a time response fast enough to observe their chemical transformations in the forest canopy; 4. Attempts will be made to identify the terpene oxidation products that have so far only been detected by their mass to charge ratio in the PTR-MS. The Broader Impacts of this activity will be in the research providing important new constraints for models predicting the formation and distribution of secondary organic aerosol, models that estimate the effects of VOC emissions on regional air quality and global climate, as well as models predicting the response of biogenic VOC emissions to climate variability and change. Multiple collaborative research efforts at Blodgett Forest will be made possible or enhanced through this award. A postdoctoral researcher will be trained through this research. Undergraduate students will also be involved. Research methodologies and results generated from this project will be integrated into classroom teaching by Prof. Goldstein.

该项目涉及挥发性有机化合物(VOC)的生物排放，将在加利福尼亚州中部的Blodgett森林遗址进行测量。快速响应质子转移反应质谱仪(PTR-MS)将用于实时原位测量生物来源的VOCs，特别是萜类化合物的浓度和通量。它们通过促进重要的大气自由基和对流层臭氧的循环，以及通过二次有机气溶胶的形成，在大气化学中发挥重要作用。在早期国家科学基金会的支持下，对穿过森林树冠的垂直浓度分布的现场测量显示，存在大量以前未报告的氧化产物，在烟雾室研究中也观察到了这些氧化产物。结果表明，在布洛吉特森林测得的夏季生态系统规模的臭氧通量中，约有一半是由于臭氧与林冠内的萜类化合物发生化学反应所致，而离开林冠的萜类化合物的通量只占实际排放的一小部分，其余的是在林冠内进行化学处理的。在这项研究的下一阶段，将追求以下目标：1.烟雾室研究将扩大到包括与加州理工大学宋飞教授合作的全面光化学氧化实验，以便在更具代表性的大气条件下识别更多相关的氧化产物；2.将使用涡旋协方差方法测量从森林冠层流出的萜烯氧化产物的垂直通量；3.将进行新的现场测量，以观察全套萜类氧化产物的时间响应足够快，以观察其在森林冠层中的化学变化；4.将尝试鉴定迄今仅通过PTR-MS中的质荷比检测到的萜烯氧化产物。这项活动的更广泛影响将体现在为预测二次有机气溶胶的形成和分布的模型、估计挥发性有机化合物排放对区域空气质量和全球气候的影响的模型以及预测生物来源的挥发性有机化合物排放对气候多变性和变化的反应的模型提供重要的新制约因素的研究中。通过这一奖项，布洛吉特森林公司的多项合作研究工作将成为可能或得到加强。通过这项研究将培养一名博士后研究员。本科生也将参与其中。这个项目产生的研究方法和结果将被整合到戈尔茨坦教授的课堂教学中。