Real-Time Visual Monitoring and High Spatiotemporal-Resolution Mapping of Air Pollutants Using a Drone-Mass Spectrometer System

Volatile organic compounds (VOCs) play multifaceted roles in the formation of air pollutants. Real-time online monitoring of VOCs is highly needed for understanding their emission sources, environmental impacts, health effects, and climate changes, as many analytical methods are limited to field detection. In this work, a flying-drone-based mass spectrometer (drone-MS) system was developed for visual real-time monitoring of complex VOCs and mapping their diffusions and distributions in the air along with spatiotemporal, geospatial, and environmental information that varies with the flight paths. Analytical performances of the drone-MS system were investigated by detecting a mixture of 18 VOCs, showing high sensitivity (limits of detection, LODs: 1.10-17.91 μg/m3; limits of quantification, LOQs: 3.84-37.61 μg/m3), good reproducibility (relative standard deviations, RSDs, intraday: 0.96-16.49%; interday: 1.17-18.28%; n = 7), and excellent quantitative ability (R2 > 0.99). Online monitoring of complex VOCs was successfully obtained at high temporal resolution (1.0 s) and high spatial resolution (2.0 m), providing an accurate source apportionment of different VOC emissions. Furthermore, practical applications of urban air quality monitoring and spatial distribution mapping of complex VOCs in air were also demonstrated. Overall, this methodology offers new possibilities for the online monitoring of complex VOCs in the air, effectively tackling the longstanding challenge of accurately characterizing complex VOCs and their diffusions and distributions.