New analytical techniques for time-resolved chemical analysis of organic matter in atmospheric aerosol particles

大气中的气溶胶颗粒物对全球气候、生态系统和人类健康产生影响（世界卫生组织，2016年; Shiraiwa等人，2017年; Andriya和Crutzen，1997年）。除了细分为不同的颗粒大小，颗粒物（PM）还可以通过其不同的化学组成来表征。最常见的是通过离线采样对PM进行采样，其中PM通过具有明确定义的气流的过滤器被吸入多个小时至数天。在第二步中，在实验室中使用分析测量技术通常与质谱（MS）耦合来进行分析。对化学成分进行详细的定性是可能的，但只能获得有关各物质浓度短期时间变化的有限信息。一个广泛应用的替代经典的离线方法是在线MS，气溶胶直接采样和分析的高时间分辨率。最常见的是气溶胶质谱仪（AMS），其中分子在电离过程中被碎片化，这只允许粗略的物质组的化学描述。特别是有机气溶胶颗粒的化学成分随时间变化很大，目前的采样和测量方法只能不完全地反映出来。因此，该项目的重点是通过应用两种新的互补方法进行时间分辨化学表征，来获得对这些粒子的源，汇和转化的新见解：i.自动离线过滤板颗粒采样器，每小时采样一次。二.萃取电喷雾离子化（EESI）Orbitrap-MS用于高时间分辨在线分析。两种方法的互补信息旨在提高对有机气溶胶颗粒的形成过程、潜在反应、汇和排放源的理解。为了实现这一点，这两种设备必须首先进行广泛的测试和表征。第一个测试阶段将在TROPOS的气溶胶室进行，由于其可控的环境条件，该室非常适合进行此类表征。为了进一步进行器械评价，在此阶段之后，在德国莱比锡的TROPOS进行了新仪器在短场活动中的首次环境应用。这些第一个腔室和环境应用旨在优化仪器并克服其操作中的潜在初始挑战。最后，在农村TROPOS研究站梅尔皮茨，德国，几个测量活动，预计。在这一阶段，主要目标是：i）测量几种有机标记物的时间分辨浓度曲线，以从环境数据中识别来源和形成过程，以及ii）探索可以通过并行应用离线和在线方法获得的潜在协同见解。

Aerosol particles in the atmosphere have impact on global climate, ecosystems, and human health (World Health Organization 2016, Shiraiwa et al. 2017, Andreae and Crutzen 1997). Besides the subdivision into different particle sizes particulate matter (PM) can also be characterized by its different chemical composition. Most commonly is PM sampled with offline sampling, where PM is sucked through a filter with a well-defined air flow for multiple hours up to days. In a second step, the analysis is carried out in the laboratory using an analytical measurement technique often with a mass spectrometry (MS) coupling. A detailed characterization of the chemical composition is possible, but only limited information on the short-term temporal variations of the respective substance concentrations are accessible. A broadly applied alternative to the classic offline approach is online MS, where the aerosol is directly sampled and analysed with high time resolution. The most common are aerosol mass spectrometer (AMS), where molecules are fragmented during ionization, which only allows a chemical description in rough groups of substances. Especially is the chemical composition of organic aerosol particles highly variable over time and is only incompletely represented by current sampling and measurement methods. Therefore, this project focusses on gaining new insights into sources, sinks, and transformations of such particles by applying two new and complementary approaches for a time-resolved chemical characterization: i. an automated offline filter-plate based particle sampler for hourly sampling intervals. ii. an extractive electrospray ionization (EESI) Orbitrap-MS for highly time-resolved online analysis. Complementary information from both approaches is intended to improve understanding in formation processes, potential reactions, sinks, and emission sources of organic aerosol particles. In order to achieve this, both devices must first be extensively tested and characterized. The first test phase is to take place at the aerosol chamber of TROPOS, which is well-suited for such characterization due to its controllable environmental conditions. For further device evaluation, this phase is followed by first ambient applications of the new instruments in short field campaigns at TROPOS in Leipzig, Germany. These first chamber and ambient applications are intended to optimize the instruments and overcome potential initial challenges in their operation. Finally, several measurement campaigns at the rural TROPOS research station Melpitz, Germany, are foreseen. In this phase, the main aims are i) to measure time-resolved concentration profiles of several organic markers to identify sources and formation processes from ambient data, and ii) to explore potential synergetic insights that can be obtained from applying both the offline and the online approach in parallel.