Real-time chemical characterisation of aviation based ultrafine particle using Orbitrap-MS

The transport sector, and particularly aviation, is an important contributor to both climate forcing and local air pollution. While measures to mitigate emissions are advancing, airport-related particulate pollution remains insufficiently characterised, especially regarding ultrafine particles (UFPs), which affect both air quality and human health. Due to their aerodynamic diameter below 0.1 µm, UFPs can penetrate deep into the pulmonary alveoli and enter the bloodstream, where they can trigger oxidative stress, inflammatory responses and other adverse physiological effects (Jonsdottir et al. 2019). Airports are recognised as UFP sources, primarily due to emissions from jet engines and auxiliary power units as well as ground support operations. With the predicted growth of the aviation sector, airport-related UFP emissions are expected to increase.

Previous research has identified jet engine lubrication oils as a distinct class of organic compounds associated with airport-related UFPs (Ungeheuer et al. 2022). These compounds contribute to the local air quality burden and can serve as specific tracer species for aircraft emissions. However, detailed chemical characterisation of these compounds remains difficult, because UFPs are due to their low mass and size hard to detect and are often masked by other organic aerosol components. Currently used approaches are mostly based on offline, filter-based techniques that are labor-intensive and offer only limited temporal resolution.

In this study, we present a novel approach for the real-time detection of JetOil tracers using in-situ Orbitrap mass spectrometry (MS). Measurements were conducted approximately 15 km from Frankfurt International Airport using a dielectric barrier discharge ion source coupled to a high-resolution Orbitrap-MS. The setup was operated in fast polarity-switching mode to simultaneously detect JetOil tracers (positive ionization) as well as possible oxidation products and sulfate (negative ionization). In parallel, a scanning mobility particle sizer (SMPS) measured size-dependent particle number and mass concentrations. Over a period of four weeks in August and September 2025, JetOil tracers were frequently detected in air masses originating from the direction of Frankfurt International Airport, coinciding with the airport’s operating hours. Simultaneously, when JetOils are present an increase in UFP concentrations in the 20–40 nm size range. In contrast, no correlation with particle-phase sulfate was observed, indicating that airport operations are not a significant source of sulfate aerosol mass in an urban environment. 

 

Jonsdottir et al. (2019) Commun. Biol., 2(1), 90.

Ungeheuer et al. (2022) Commun Earth Environ., 3(1), 319.