Name: MPAN, Methacrolein, Isobutyraldehyde, and 231MBO photoxidation experiments
Time format and units: Experiment time (minutes, local)

Organization

Caltech Atmospheric Chamber

Chamber

Near/Far Bag 2012-2015 (Tran)

Description

Photoxidation of synthesized methacryloyl peroxynitrate (MPAN) to understand its pathways of SOA formation, leading to 2-methylglyceric acid in the particle phase. It is hypothesized that MPAN produces an unstable intermediate called HMML (hydroxymethyl methyl-a-lactone) that ring opens when it hits a surface, with co-product NO3. Some experiments were done with alpha-pinene as an NO3 scavenger, with the production of pinene nitroxy hydroperoxide (PNP, m/z 316 C10H17NO5) evidence of the alpha-pinene + NO3 chemistry. Photoxidation of methacrolein (MACR) was performed for comparison. Photooxidation of 2-methyl-but-3-ene-1-ol (231MBO) and isobutyraldehyde were performed because they are (or can produce) analogous compounds that will give insight into the oxidation mechanism. Experiments were mainly performed dry and with no seeds, although 2 experiments were performed on with varying particle liquid water on ammonium sulfate (AS) seeds. Note that particle wall loss has already been applied to SMPS data, but the raw data are also provided as well as the wall loss kinetic parameters.

Collaborators:

• Tran Nguyen (UC Davis)
• Paul Wennberg (Caltech)

Download this Experiment Set (3.54 MB)

Cite all experiments in this Experiment Set:

• https://doi.org/10.5065/00h7-hj39
• https://doi.org/10.5065/dak8-mj80
• https://doi.org/10.5065/xhk4-ar88
• https://doi.org/10.5065/5ax6-q953
• https://doi.org/10.5065/3gn5-ga41
• https://doi.org/10.5065/0ezj-ky85
• https://doi.org/10.5065/wqnk-0d03
• https://doi.org/10.5065/5wrm-mc89
• https://doi.org/10.5065/5vey-7492
• https://doi.org/10.5065/7p60-q673
• https://doi.org/10.5065/cfwy-wk15
• https://doi.org/10.5065/b2h3-8665
• https://doi.org/10.5065/b9xa-zt95
• https://doi.org/10.5065/vmct-p141

Publications associated with this Experiment Set:

• Mechanism of the hydroxyl radical oxidation of methacryloyl peroxynitrate (MPAN) and its pathway toward secondary organic aerosol formation in the atmosphere