Field-portable volatile trapping system for marine and atmospheric research

我们的小组研究海洋气候活跃气体的生产、分布和生物地球化学循环，包括二甲硫醚（DMS）和其他重要的挥发性有机化合物（VOC）。我们的目标是研究这些化合物在海气界面的来源和命运，以更好地了解全球气候反馈。二甲硫醚通过产生阻挡太阳辐射的大气气溶胶来影响地球气候。这种分子在碳、硫和能量跨海洋营养级的转移中也发挥着相当大的作用。我们最近开发了一种强大的分析方法，使用质谱法来测量海水中超低水平的 DMS 和其他 VOC。该方法适用于检测所有海洋环境中的这些化合物，其浓度跨多个数量级，并实现了其他方法无法实现的独特应用。这些应用包括用于测量海洋 DMS 周转率的稳定同位素孵化、低氧水中 DMS 微区的检测和表征，以及大气中痕量 VOC 的分析。 我们的新分析方法是一种强大的研究工具，具有在海洋和大气科学领域开辟世界领先研究新路线的强大潜力。然而，所需的仪器笨重、精密且昂贵，因此无法满足海上研究的严格要求。为了保持该仪器的长期性能，并将我们的方法的实用性扩展到偏远的现场情况（例如基于直升机的北极采样），我们制定一种新的样品采集策略以将现场采样与基于实验室的分析脱钩至关重要。我们正在申请资金来建造一个全自动气体捕集系统，这将使我们能够离线进行定量分析，从而无需在未来的探险中将质谱仪带到海上。我们建议制造定制的挥发性捕集歧管，即大型且可扩展的可单独寻址的商用热脱附管阵列，允许在运回实验室进行 MS 分析之前，对从海水和/或大气样品中提取的 DMS 和其他 VOC 进行现场收集、处理和稳定。拟议的系统将用于支持总部训练，并使我们能够极大地扩展我们的现场采样能力。

Our group examines the production, distribution and biogeochemical cycling of oceanic climate-active gases, including dimethyl sulfide (DMS), and other important volatile organic compounds (VOCs). Our aim is to study the sources and fate of these compounds across the air-sea interface, to better understand global climate feedbacks. Dimethyl sulfide impacts Earth's climate through the production of atmospheric aerosols that block incoming solar radiation. This molecule also plays a considerable role in the transfer of carbon, sulfur and energy across marine trophic levels. We have recently developed a powerful analytical method using mass spectrometry to measure DMS and other VOCs in seawater at ultra-low levels. The method is suitable for detecting these compounds in all marine environments, across many of orders of magnitude in concentration, and has enabled unique applications, which are not possible with other methods. These applications include stable isotope incubations to measure the turnover rates of marine DMS, the detection and characterization of DMS micro-zones within low oxygen waters, and the analysis of trace VOCs in the atmosphere. Our new analytical method is a powerful research tool, with strong potential to open new lines of world-leading research in ocean and atmospheric sciences. However, the required instrumentation is cumbersome, delicate, and expensive, and thus not designed to handle the rigors of sea-going research. In order to maintain long-term performance of this instrument, and to extend the utility of our methods to remote field situations (e.g. helicopter-based Arctic sampling), it is critical that we develop a new strategy for sample collection to decouple field sampling from the lab-based analysis. We are requesting funds to build a fully-automated gas trapping system, which will allow us to take quantitative analysis offline, eliminating the need to bring the mass spectrometer to sea on future expeditions. We propose fabrication of a custom-built Volatile Trapping Manifold a large and expandable array of individually addressable commercial thermal desorption tubes, allowing field-based collection, processing and stabilization of DMS and other VOCs extracted from seawater and/or atmospheric samples, before transport back to the lab for MS analysis. The proposed system will be used to support HQP training, and allow us to greatly extend our field-based sampling capabilities.