Kroflič Ana, Anders Janine, Drventić Ivana, Mettke Peter, Böge Olaf, Mutzel Anke, Kleffmann Jörg, Herrmann Hartmut
Department of Analytical Chemistry, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia.
Atmospheric Chemistry Department (ACD), Leibniz-Institute for Tropospheric Research (TROPOS), Permoserstraße 15, 04318 Leipzig, Germany.
ACS Earth Space Chem. 2021 May 20;5(5):1083-1093. doi: 10.1021/acsearthspacechem.1c00014. Epub 2021 Apr 12.
Atmospheric nitrophenols are pollutants of concern due to their toxicity and light-absorption characteristics and their low reactivity resulting in relatively long residence times in the environment. We investigate multiphase nitrophenol formation from guaiacol in a simulated atmospheric aerosol and support observations with the corresponding chemical mechanisms. The maximal secondary organic aerosol (SOA) yield (42%) is obtained under illumination at 80% relative humidity. Among the identified nitrophenols, 4-nitrocatechol (3.6% yield) is the prevailing species in the particulate phase. The results point to the role of water in catechol and further 4-nitrocatechol formation from guaiacol. In addition, a new pathway of dark nitrophenol formation is suggested, which prevailed in dry air and roughly yielded 1% nitroguaiacols. Furthermore, the proposed mechanism possibly leads to oligomer formation via a phenoxy radical formation by oxidation with HONO.
大气中的硝基酚因其毒性、光吸收特性以及低反应活性导致在环境中的停留时间相对较长而成为令人关注的污染物。我们在模拟大气气溶胶中研究了愈创木酚多相硝基酚的形成，并通过相应的化学机制来支持观测结果。在80%相对湿度光照条件下可获得最大二次有机气溶胶（SOA）产率（42%）。在已鉴定出的硝基酚中，4 - 硝基邻苯二酚（产率3.6%）是颗粒相中的主要成分。结果表明水在邻苯二酚以及愈创木酚进一步形成4 - 硝基邻苯二酚过程中所起的作用。此外，还提出了一条黑暗条件下硝基酚形成的新途径，该途径在干燥空气中占主导，大约生成1%的硝基愈创木酚。此外，所提出的机制可能通过与HONO氧化形成苯氧基自由基导致低聚物的形成。
