Date of Award

12-2017

Degree Name

Master of Science

Department

Chemistry

First Advisor

Dr. Steven Bertman

Second Advisor

Dr. Michael Barcelona

Third Advisor

Dr. Andre Venter

Keywords

Isoprene, APAN, Nox, Photooxidation, peroxyacrylic nitric anhydride

Access Setting

Masters Thesis-Open Access

Abstract

Peroxyacyl nitrates (PANs, RC(O)OONO2) are of great importance in atmospheric chemistry. They act as transporters of reactive nitrogen, and radical delivery agents. There are no known natural emission sources of PANs; they are produced through reaction of volatile organic compounds (VOCs) and nitrogen oxides (NOx) in the atmosphere.

VOCs can enter the atmosphere through biogenic and anthropogenic pathways. It has been estimated that isoprene makes up 70% of the biogenic VOCs (BVOCs) emitted annually. Isoprene has been shown to impact ozone levels in both rural and urban areas by sequestering and transporting NOx in the form of isoprene nitrates and PANs. In addition, isoprene photooxidation leads to the production of a significant amount of SOA.

Dozens of experiments performed in nonreactive “smog” chambers containing high levels of isoprene and NOx have consistently produced a PAN-like compound that is absent from the literature of isoprene chemistry. Evidence for the identification of this compound was compiled including thermal decomposition rate, and GC-ECD retention time comparison of the PAN-like compound with APAN standards. Mass spectra of APAN standards were compared to a mass spectrum obtained from isoprene oxidation and found to be identical confirming that the PAN-like compound produced from isoprene oxidation was APAN.

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