Real-time Measurements in Real-world Samples: Fate and Distribution of Trace Organic Contaminants by Direct Mass Spectrometry

该研究项目的重点是开发和应用创新的实时质谱（MS）技术，用于直接和连续测量环境和人类健康的分子决定因素。Direct MS是一个非常强大的分析平台，可实现高通量、时间分辨和原位测量。这些独特的能力，解决了几个长期存在的限制，目前的理解的命运和分布的污染物的新出现的关注，通过提供分子水平的信息，在复杂的样品中的应用，在实时监测和先进的时空分析。这项研究将1）为新的污染物类别开发新的直接采样方法，2）研究复杂介质中的环境化学过程，3）动员MS在空气，水和沉积物中进行现场测量。这些目标是通过开发灵敏和选择性的MS方法来实现的，这些方法快速，简单，耐用。在没有色谱分离的情况下，直接MS依赖于样品引入方法、电离机制和质谱仪赋予的选择性。在膜引入方法中，分子渗透到连续注入质谱仪的受体中。了解控制质量传递的因素使我们能够使用新材料，电梯度和化学改性剂来提高选择性和设计新的基于膜的策略。场不对称波形离子迁移谱代表了与直接MS应用的理想配对，因为它提供了快速、正交分离（基于差分迁移率）。它很容易与高分辨率，实验室仪器和低成本，便携式MS配对，为随后的现场应用提供了开发方法的机会。时间分辨质谱技术提供了独特的洞察机制的化学和物理过程，影响环境中污染物的转化。采用膜引入MS技术跟踪非均质样品中分析物浓度的变化，包括微塑料上痕量污染物的吸附和油砂工艺沃茨中环烷酸的光化学降解。质子转移反应质谱仪提供了挥发性有机化合物的连续道路测量，产生了在邻域尺度上绘制的化学浓度和成分信息，以“指纹”来源和分配贡献。 本文所述的研究通过开发下一代方法来提供真实世界样品中的实时分子水平信息，为环境化学分析开辟了重要的新领域。“在需要的时候”和“在需要的地方”提供化学品信息，能够以前所未有的时空分辨率进行环境评估和取证。因此，这项研究直接有助于环境保护和健康的社区。

This research program centres on the development and application of innovative real-time mass spectrometry (MS) techniques for the direct and continuous measurement of molecular determinants of environmental and human health. Direct MS is an extremely powerful analytical platform that enables high throughput, time-resolved, and in-situ measurements. These unique capabilities address several long-standing constraints to current understanding of the fate and distribution of contaminants of emerging concern by providing molecular level information in complex samples with applications in real-time monitoring and advanced spatiotemporal analysis. This research will 1) develop novel direct sampling methods for new contaminant classes, 2) study environmental chemical processes in complex media, and 3) mobilize MS for in-field measurements in air, water, and sediments. These goals are realized by developing sensitive and selective MS methods that are fast, simple, and robust. In the absence of chromatographic separation, direct MS relies on selectivity imparted by the sample introduction method, ionization mechanism, and the mass spectrometer. In membrane introduction methods, molecules permeate into an acceptor which is continuously infused into a mass spectrometer. Understanding factors that control mass transport allow us to improve selectivity and design novel membrane-based strategies using new materials, electrical gradients, and chemical modifiers. Field asymmetric waveform ion mobility spectrometry represents an ideal pairing with direct MS applications as it provides fast, orthogonal separation (based on differential mobility). It is readily paired with high resolution, lab-based instruments and lower cost, portable MS, providing the opportunity to develop methods for subsequent in-field applications. Time-resolved MS techniques provide unique insight into the mechanisms of chemical and physical processes that affect the transformation of contaminants in the environment. Membrane introduction MS techniques are employed to follow changes in the concentration of analytes in heterogeneous samples including sorption of trace contaminants on microplastics and photochemical degradation of naphthenic acids in oil sands process waters. Proton-transfer reaction MS provides continuous on-road measurements of volatile organic compounds that yields chemical concentrations mapped at the neighborhood scale and compositional information to `finger-print' sources and apportion contributions. The research described here opens important new territory in environmental chemical analysis by developing next-generation methods to provide real-time molecular level information in real-world samples. Providing chemical information `when' and `where' it is needed enables environmental assessment and forensics at unprecedented spatiotemporal resolution. As such, this research contributes directly to environmental protection and healthy communities.