This work provides a comprehensive sensitivity calibration of a chemical ionization instrument commonly used in field measurements for the measurement of the toxic isomers methyl isocyanate and hydroxyacetonitrile that are found in the atmosphere. The results from this work have demonstrated that the hydroyacetonitrile isomer was observed in previous field studies rather than the stated identification of methyl isocyanate.

The gas-phase reactions of organic compounds in the atmosphere are a crucial step in the degradation of anthropogenic and biogenic emissions and the formation of secondary pollutants. This work is an attempt to produce a dataset that is as comprehensive as possible regarding the multitude of chemicals that react in the atmosphere. We find that we are able to make substantial improvements upon previous compendia and that this progress will help improve our understanding of atmospheric chemistry.

We have discovered a new compound in the atmosphere, octafluorooxolane (c-C₄F₈O), from measurements in archived air samples. From our laboratory studies, we find that c-C₄F₈O is a very powerful greenhouse gas thereby contributing to global warming, and that it has a very long atmospheric lifetime of more than 3500 years. Based on our measurements we could reconstruct its atmospheric evolution over more than 4 decades. Based on this, we could estimate the global emissions of c-C₄F₈O.

A lack of policy-relevant metrics for hydrochlorofluorocarbons (HCFCs) regulated in the Montreal Protocol is addressed by providing reliably estimated metrics for all HCFCs included in the protocol. This research provides reliable policy-relevant metrics (e.g., atmospheric lifetimes, ozone depletion and global warming potentials) based on well-established estimation methods. The results from this work provide the Montreal Protocol the information needed for informed policy decisions.

The formation of SOA and sulfate aerosols from the photooxidation of gasoline vehicle exhaust (GVE) when mixing with SO₂ was investigated in a smog chamber. We found that the presence of GVE enhanced the conversion of SO₂ to sulfate predominantly through reactions with stabilized Criegee intermediates. On the other hand, the elevated particle acidity enhanced the SOA production from GVE. This study indicated that SO₂ and GVE could enhance each other in forming secondary aerosols.