A new ozone denuder for aerosol sampling based on an ionic liquid coating

摘要

A new ionic liquid 1-octyl-3,5-dimethylpyridinium iodide ([O35LUT] ~+[I]~-) was synthesized and utilized as coating for an ozone denuder device based on a high-volume aerosol sampler (30 m ~3h~(-1)). Particle transmission of the denuder was studied, and over 99% of particles ranging from 10 to 2,500 nm were transmitted. The device, containing 4.66 g of ionic liquid, was used outdoors, under dry and damp atmospheric conditions. In order to expose the device to an average concentration of 120 ppbv (240 μg m~(-3)) of ozone in air, an additional production of ozone was directly injected into the denuder. Under these conditions, over 97% of ozone was removed for approximately 120 h (5 days). Therefore, iodide-based ionic liquids can be used as a new alternative to conventional denuder coatings in order to reduce artifacts occurring during sampling of particulate matter. Future applications are not limited to ozone removal for specific aerosol sampling methods.