engleski

Nitroaromatic constituents of water soluble organic aerosols: Identification, abundance and possible sources

The (trans)formation, properties, and removal of organic particles remain one of the least understood aspects of atmospheric chemistry despite of their importance for both human health and climate change. Herein, nitrogen containing constituents of atmospheric organic aerosols (OA) associated with anthropogenic activities, biomass-burning (BB) and marine biological sources have considerable role. Among the largest and important groups of industrial chemicals in use today are potentially toxic nitroaromatic compounds (NACs). NACs are also confirmed as important secondary organic aerosol (SOA) constituents and the major contributors to atmospheric brown carbon1. In particular, NACs as (methyl)nitrocatehols and nitroguaiacols have recently come into the focus as a significant fraction of water soluble OA, being secondary tracers of BB emissions as well as aged anthropogenic aerosols, whose (trans)formation and properties in the atmospheric waters are only beginning to be understood2-4. A comprehensive study on seasonal aerosol size-segregated (size range: 0.038-15.6 μm) water soluble organic matter (WSOM), with a focus on its specific NACs (e.g. 4-nitrocatechol ; methyl nitrocatechols, (di)nitrophenols, methyl nitrophenols, nitrosalicylic acids, (di)nitroguaiacols, etc), through investigation of their molecular level speciation and quantification using LC/ESI-MS/MS will be presented. The obtained data were correlated with those for levoglucosan as well as with aerosol mass, total carbon, and carbon content in WSOM. On the basis of seasonal data collected at an urban background environment of Ljubljana, Slovenia, an insight into the ambient characteristics of NACs (including several new) will be given. In addition a critical evaluation of their potential sources and transformation processes in the atmosphere will be discussed.

SOA ; nitroaromatics ; LC-MS

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