Cooperative Institute for Research in Environmental Sciences at the University of Colorado Boulder

Atmospheric Chemistry Program Seminar

Chemistry of Volatile Organic Compounds in the Atmosphere

by Joost de Gouw,
ANYL faculty, CU Boulder (1/2 seminar)

"Volatile organic compounds (VOCs) are released from many different natural and man-made sources to the atmosphere. VOCs are removed by different oxidants on time scales of minutes to months with oxidized VOCs, ozone and fine particles as a result. These processes affect air quality and climate and are a challenge to understand due to the large number of different VOCs that are released to the atmosphere and the analytical difficulties in measuring all of these compounds as well as their oxidation products.

In our laboratory, we make measurements of VOCs by proton-transfer-reaction time-of-flight mass spectrometry (PTR-TOF) and gas chromatography mass spectrometry (GC-MS). PTR-TOF allows measurements of many different VOCs with high time resolution and without the need for pre-separation or sample treatment. GC-MS allows higher chemical detail, but at the cost of time resolution. We also combine these methods to better understand the compounds that are detected by PTR-TOF in different environments.

Several different ongoing and future projects will be presented in this seminar. First, we use PTR-TOF for measurements of VOCs in indoor environments. From the results we learn about the sources of VOCs from people, chemical products and building materials, the chemical transformations of these VOCs and other loss process such as surface uptake and ventilation to the atmosphere. Second, we are working on the emissions and chemistry of VOCs released from volatile chemical product (VCP) use to the atmosphere, which was recently discovered to be the dominant source of VOCs in urban air. In this research we make measurements of VOCs in urban air, separate the different emission sources and describe the chemical transformations of VOCs after emission. Finally, we are working on a chamber study to better understand the formation of secondary organic aerosol from biogenic VOCs."

and

Organic nitrogen chemistry: Recent results and future projects

by Eleanor Browne,
ANYL faculty, CU Boulder (1/2 seminar)

"Organic nitrogen is a ubiquitous atmospheric component that affects biogeochemistry, air quality, and climate. Assessing the impact of organic nitrogen on these processes remains challenging because traditional measurement techniques have lacked the sensitivity and chemical resolution to characterize the speciation and chemistry of organic nitrogen. Here, I will discuss measurements made with protonated ethanol cluster chemical ionization time-of-flight mass spectrometry during the Holistic Interactions of Shallow Clouds, Aerosols, and Land-Ecosystems (HI-SCALE) campaign at the Southern Great Plains research station in Lamont, Oklahoma. As the site is located in an agricultural region, reduced nitrogen compounds are prevalent. I will present measurements of novel compounds including imines and urea and will discuss the sources and sinks of compounds at this site. Finally, I will discuss research opportunities in our group. These include further measurements at SGP in Spring 2020 and Fall 2021 as well as instrument development and chemical transport modeling."

 

date

Monday, September 16, 2019
12:00pm to 1:00pm

location

Ekeley S274

contact

Anne.Handschy@Colorado.EDU