BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//132.216.98.100//NONSGML kigkonsult.se iCalcreator 2.20.4//
BEGIN:VEVENT
UID:20250928T211928EDT-04683svE1W@132.216.98.100
DTSTAMP:20250929T011928Z
DESCRIPTION:Zoom link: https://mcgill.zoom.us/j/7468754607\n\nAbstract:\n\n
 During their lifetime\, organic aerosols will be subjected to atmospheric 
 processing including exposure to sunlight. Photochemistry of chromophoric 
 organic matter within aerosols can produce in-situ reactive oxygen species
  (ROS) capable of transforming chemical and physical properties of aerosol
 s\, with implications for air quality and climate. Singlet oxygen (1O2) is
  a well-known ROS in biology and in surface waters\, yet there is little k
 nowledge of its atmospheric sources and sinks\, and consequently of its ab
 ility to alter aerosol chemistry with implications on health and aerosol-c
 loud interactions.\n\n \n\nTo address this knowledge gap\, we generated se
 condary organic aerosols (SOA) from aromatic anthropogenic precursors in a
  laboratory smog chamber. We then extracted the collected SOA filters and 
 submitted the soluble extracts to atmospherically-relevant photochemical c
 onditions of UVA and UVB light at room temperature. Using furfuryl alcohol
  as a probe for 1O2\, we determined steady-state concentrations of this ox
 idant using liquid chromatography and calculated 1O2 quantum yields for ea
 ch SOA sample. Subsequent quantification of OH radicals and peroxides allo
 wed for the comparison of degradation rates between ROS. We find that mole
 cules such as amino acids\, organo-nitrogen compounds and phenolic compoun
 ds have a shortened lifetime by more than half when 1O2 reactivity is take
 n into consideration. We further evaluated the effect of photochemical agi
 ng by 1O2 on the ability of SOA to act as cloud condensation nuclei\, and 
 found that despite no 1O2 production in a-pinene SOA\, aging led to increa
 ses hygroscopicity. Our ongoing work is looking at the photoproduction of 
 1O2 in ambient PM10 filter samples in Switzerland and its potential source
  apportionment\, as well as sources of 1O2 production with indoor photoche
 mistry. The aim of this research on atmospheric 1O2 is to characterize its
  understudied role in aqueous aerosol chemistry.\n\nBio:\n\nNadine is an a
 tmospheric organic chemist interested in chemical mechanisms in the gas ph
 ase and in the aerosol phase. She has a BSc and MSc in organic chemistry w
 ith experience working in pharmaceutical industries in Canada and in Germa
 ny. She then obtained a PhD in atmospheric chemistry from the University o
 f Toronto in 2015\, working on the atmospheric fate of organo-nitrogen pol
 lutants. After working at an air quality consulting company in South Afric
 a\, she moved to Switzerland to pursue an NSERC PDF at ETH Zurich studying
  the role of photochemistry on aerosol-cloud interactions. In 2018\, she s
 tarted her independent career at ETH Zurich funded by an Ambizione grant f
 rom the Swiss National Science Foundation hosted in the environmental chem
 istry and atmospheric physics groups. In January 2021\, Nadine started as 
 an assistant professor in Chemistry at UBC. Ongoing research interests in 
 the NBD Group include atmospheric chemical mechanisms of pollutants and of
  aerosols found indoors and outdoors\, as well as cloud chemistry and the 
 mechanism of atmospheric ice nucleation.\n
DTSTART:20210202T180000Z
DTEND:20210202T193000Z
SUMMARY:Chemical Society Seminar: Nadine Borduas-Dedekind - Singlet oxygen 
 in the atmosphere: Its photoproduction within aqueous organic aerosols fro
 m laboratory\, outdoor and indoor sources
URL:/chemistry/channels/event/chemical-society-seminar
 -nadine-borduas-dedekind-singlet-oxygen-atmosphere-its-photoproduction-326
 617
END:VEVENT
END:VCALENDAR