Dang Audrey J, Kreisberg Nathan M, Cargill Tyler L, Chen Jhao-Hong, Hornitschek Sydney, Hutheesing Remy, Turner Jay R, Williams Brent J
Department of Energy, Environmental & Chemical Engineering, Washington University in St. Louis, St. Louis, MO 63130, United States.
Aerosol Dynamics Inc., Berkeley, CA 94710, United States.
Atmos Meas Tech. 2024;17(7):2067-2087. doi: 10.5194/amt-17-2067-2024. Epub 2024 Apr 15.
Volatile organic compounds (VOCs) have diverse functionality, emission sources, and environmental fates. Speciated measurements of their spatiotemporal variability are thus key to understanding their impacts on air quality, health, and climate. Networks of passive samplers can be used to map VOC concentrations, or in situ instruments can be deployed on mobile platforms. Limitations of existing in situ instruments include high cost, identification of non-target species, differentiation of isomeric species, and low time resolution, which limits how quickly an area can be spatially mapped with mobile measurements. This work describes the development of the Multichannel Organics In situ enviRonmental Analyzer (MOIRA), which has been designed for in situ mobile measurements of target and non-target VOCs from the cargo area of a hybrid hatchback wagon vehicle. Staggered sample collection and analysis by four thermal desorption collectors, four miniature gas chromatography (GC) heaters, and two compact residual gas analyzer (RGA) mass spectrometer (MS) detectors enable continuous measurements at a 10 min time resolution. Non-target species and structural isomers can be identified with electron ionization (EI), and species detected include alkanes (from pentane to pentadecane) and aromatics, as well as more oxidized species such as aldehydes, esters, and carboxylic acids. The instrument is characterized in the laboratory under different environmental conditions and in two pilot field studies of indoor air in a single-family residence and of ambient air during a mobile deployment.
挥发性有机化合物（VOCs）具有多种功能、排放源和环境归宿。因此，对其时空变异性进行特定测量是了解它们对空气质量、健康和气候影响的关键。被动采样器网络可用于绘制VOC浓度图，或者可在移动平台上部署现场仪器。现有现场仪器的局限性包括成本高、非目标物种的识别、同分异构体的区分以及时间分辨率低，这限制了利用移动测量对一个区域进行空间测绘的速度。这项工作描述了多通道有机物质现场环境分析仪（MOIRA）的开发，该仪器设计用于对混合动力掀背旅行车货舱中的目标和非目标VOCs进行现场移动测量。通过四个热解吸收集器、四个微型气相色谱（GC）加热器和两个紧凑型残余气体分析仪（RGA）质谱仪（MS）探测器进行交错式样品采集和分析，能够以10分钟的时间分辨率进行连续测量。非目标物种和结构异构体可以通过电子电离（EI）进行识别，检测到的物种包括烷烃（从戊烷到十五烷）和芳烃，以及更多氧化态的物种，如醛、酯和羧酸。该仪器在不同环境条件下的实验室中以及在一项针对单户住宅室内空气和一项移动部署期间环境空气的两项试点现场研究中进行了表征。
