AGS-PRF: Molecular Level Characterization of Amino Acids in Atmospheric Aerosols

AGS-PRF：大气气溶胶中氨基酸的分子水平表征

• 批准号: 1524211
• 负责人: Coty Jen
• 金额: $ 8.6万
• 依托单位: Jen Coty N
• 依托单位国家: 美国
• 项目类别: Fellowship Award
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-01 至 2017-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1524211&HistoricalAwards=false
• 关键词: AGS; PRF; Molecular; Level; Characterization

This Postdoctoral Research Fellowship is focused on the investigation of amino acids in the atmosphere and their contribution to the nitrogen content of atmospheric particles. It will establish an instrumental method for characterizing amino acids in gas and particle phases. Samples from several recent field campaigns will be analyzed for amino acid content. This project will improve the understanding of how biological activities, both natural and anthropogenic, that lead to the emission of amino acids influence Earth's nitrogen cycle. The specific objectives of the proposed project are to: (1) Calibrate the Semi-Volatile Thermal desorption Aerosol Gas chromatograph/mass spectrometer (SV-TAG) for targeted amino acids by using chemical standards, and compare it to a gas phase instrument, Cluster Chemical Ionization Mass Spectrometer (Cluster CIMS), and a particle phase instrument, two-dimensional GC with electron impact or vacuum UV ionization coupled to a high resolution time-of-flight MS (GCxGC-EI/VUV-HR-TOFMS); (2) Identify and quantify amino acids from SV-TAG data and filter samples collected during previous field campaigns in the Amazon Rainforest, Southeastern United States, and an indoor classroom; and (3) Determine the partitioning coefficients of targeted free amino acids in atmospheric aerosols from various environments. Large discrepancies between predicted and measured partitioning coefficients indicate that free amino acids are condensing and reacting in the particles. This supports the hypothesis that amino acids react in the particle phase to form stable, low volatility compounds that contribute to the observed excess nitrogen (i.e., difference between total nitrogen and inorganic nitrogen amounts) in atmospheric particles and fog/cloud droplets.

该博士后研究奖学金的重点是研究大气中的氨基酸及其对大气颗粒氮含量的贡献。 它将建立一种表征气相和颗粒相氨基酸的仪器方法。 来自最近几次实地活动的样品将被分析氨基酸含量。 该项目将提高人们对导致氨基酸排放的自然和人为生物活动如何影响地球氮循环的理解。 该项目的具体目标是：（1）使用化学标准对目标氨基酸的半挥发性热脱附气溶胶气相色谱/质谱仪（SV-TAG）进行校准，并将其与气相仪器、簇化学电离质谱仪（Cluster CIMS）和颗粒相仪器、电子轰击或真空紫外电离的二维气相色谱仪进行比较 与高分辨率飞行时间 MS (GCxGC-EI/VUV-HR-TOFMS) 联用； (2) 从之前在美国东南部亚马逊雨林和室内教室进行实地活动期间收集的 SV-TAG 数据和过滤样本中识别和量化氨基酸； (3)确定目标游离氨基酸在不同环境的大气气溶胶中的分配系数。预测和测量的分配系数之间的巨大差异表明游离氨基酸在颗粒中凝结和反应。这支持了这样的假设：氨基酸在颗粒相中反应形成稳定的、低挥发性的化合物，这些化合物导致大气颗粒和雾/云滴中观察到的过量氮（即总氮和无机氮量之间的差异）。