Drone-based needle trap device array coupled with portable mass spectrometry for onsite analysis of hazardous air pollutants.

BACKGROUND

Onsite detection of hazardous air pollutants is crucial for environmental monitoring, as such pollutants can be rapidly released and diffused from emission sources into the surrounding and upper air, often occurring in locations that are difficult or unsafe for human access. Traditional field sampling approaches pose challenges in providing timely molecular identification and spatial characterization of pollutants under such dynamic and hard-to-reach conditions. Therefore, the development of rapid, sensitive, and field-deployable analytical strategies for air pollutant monitoring is highly needed.

RESULTS

We developed a drone-based needle trap device (NTD) array for air sampling at different environmental conditions. The NTD array enabled simultaneous sampling at multiple heights during a single flight, and samples collected by the NTD were subsequently analyzed using portable gas chromatography-mass spectrometry (GC-MS), allowing rapid identification and quantification of air pollutants within minutes. Acceptable analytical performance was achieved, including low detection limits (at ppbv level), excellent linearity (R2 > 0.99), good reproducibility (RSD <20%, n = 6), and fast analysis speed (within minutes). Onsite environmental analysis was successfully demonstrated for air samples from biogenic, anthropogenic, and special environments involving hazardous volatile releases. In particular, the vertical diffusion behavior of VOCs was also investigated, showing the spatial distribution of air pollutants in the air.

SIGNIFICANCE: The integration of a drone-based NTD array with portable GC-MS enables onsite detection and simultaneous multi-height sampling during a single flight, allowing high-resolution mapping of vertical concentration gradients of hazardous air pollutants. This approach provides an effective and cost-efficient method for characterizing pollutant distributions in complex or hard-to-access environments and offers new possibilities for field atmospheric monitoring.