Development and application of new analytical approaches to understand the chemistry of the atmospheric condensed phase

开发和应用新的分析方法来了解大气凝聚相的化学性质

• 批准号: RGPIN-2018-05990
• 负责人: Young, Cora
• 金额: $ 3.5万
• 依托单位: York University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=713986
• 关键词: Development; application; new; analytical; approaches

Progress in areas of environmental chemistry requiring urgent attention is limited by available analytical methods. My research group develops new techniques and uses them to examine sources, impacts, and fate of pollutants. Over the next five years, we will use this approach to target two critical areas of uncertainty: persistent pollutant transport and climate change. Both issues are at crucial junctures for international regulation. Persistent pollutants can undergo long-range transport and impact areas far from their release. Short-chain perfluorocarboxylic acids (scPFCAs) are persistent and potentially toxic. We recently showed scPFCA accumulation in the Arctic was caused by the regulated replacement of ozone-depleting chlorofluorocarbons with alternatives. A 2016 policy amendment will dramatically change the sources of scPFCAs, impacting transport and fate. We will develop two techniques that will represent the first real-time methods for gas- and aerosol-phase scPFCAs. These will enable us to probe gas-surface interactions and physical properties in flowtube studies and make the first real-time measurements of gas- and aerosol-phase scPFCAs. Using a new offline method for scPFCAs, we will also collect and analyze atmospheric deposition samples. Proposed laboratory and field measurements are critical to inform chemical fate models and assess the environmental impacts of changing regulation. This work will involve 11 HQP (3 PhD, 3 MSc, 5 undergraduate). Organic aerosols released from burning vegetation have climate-warming properties that are not well understood, impeding their accurate inclusion in climate models. Much of this uncertainty is derived from poorly-characterized water-soluble organic compounds, known as brown carbon (BrC). Our new method for offline analysis showed that BrC was composed of molecules much larger than previously believed and that it could not be detected using mass spectrometry (MS) with electrospray ionization. Building on this, we will explore MS ionization techniques to identify a more suitable method for BrC characterization. The new technique will be used to study impacts of atmospheric processing on BrC by characterizing samples chemically aged in a flowtube and samples collected from controlled burn studies. We will interface our method to a sampling system to create the first BrC online system coupled to chemical separation, which will be applied in fire-impacted areas. The improved understanding of chemical structure and fate of BrC provided by our measurements will be critical for improving climate models that underpin international regulation. This work will involve 4 HQP (2 PhD, 2 undergraduate). Through development and application of innovative new analytical methods to laboratory and field measurements, my group will provide fundamental chemical understanding that is essential to effective environmental regulation.

需要迫切关注的环境化学领域的进展受到现有分析方法的限制。我的研究小组开发了新技术，并利用它们来研究污染物的来源、影响和归宿。在接下来的五年中，我们将利用这种方法来解决两个关键的不确定性领域：持久性污染物迁移和气候变化。这两个问题都处于国际监管的关键时刻。 持久性污染物可以进行长距离迁移并影响远离其释放的区域。短链全氟羧酸 (scPFCA) 具有持久性和潜在毒性。我们最近表明，北极地区 SCPFCA 的积累是由于用替代品对消耗臭氧层的氯氟烃进行有管制的替代造成的。 2016 年的政策修正案将极大地改变短链全氟辛烷磺酸的来源，影响运输和命运。我们将开发两种技术，代表气相和气溶胶相 scPFCA 的第一个实时方法。这些将使我们能够在流管研究中探测气体-表面相互作用和物理特性，并首次实时测量气相和气溶胶相 scPFCA。我们还将使用一种新的 scPFCA 离线方法来收集和分析大气沉积样本。拟议的实验室和现场测量对于为化学归宿模型提供信息并评估不断变化的法规对环境的影响至关重要。这项工作将涉及 11 名 HQP（3 名博士、3 名硕士、5 名本科生）。 燃烧植被释放的有机气溶胶具有导致气候变暖的特性，但目前尚不清楚，这阻碍了将其准确纳入气候模型。这种不确定性很大程度上源自特征较差的水溶性有机化合物，即棕碳 (BrC)。我们的离线分析新方法表明，BrC 由比之前认为的大得多的分子组成，并且使用电喷雾电离质谱 (MS) 无法检测到它。在此基础上，我们将探索 MS 电离技术，以确定更适合 BrC 表征的方法。这项新技术将通过表征在流量管中化学老化的样品以及从受控燃烧研究中收集的样品来研究大气处理对 BrC 的影响。我们将把我们的方法与采样系统连接起来，创建第一个与化学分离相结合的 BrC 在线系统，该系统将应用于受火灾影响的地区。通过我们的测量，加深对 BrC 化学结构和命运的了解，对于改进支撑国际监管的气候模型至关重要。这项工作将涉及 4 名 HQP（2 名博士，2 名本科生）。 通过在实验室和现场测量中开发和应用创新的新分析方法，我的小组将提供对有效环境监管至关重要的基本化学理解。