10.1021/es403340g.s001
Michael
I. Jacobs
Michael
I.
Jacobs
Adam I. Darer
Adam I.
Darer
Matthew J. Elrod
Matthew J.
Elrod
Rate Constants
and Products of the OH Reaction with
Isoprene-Derived Epoxides
American Chemical Society
2013
Master Chemical Mechanism Version 3.2
water content
gas phase OH oxidation
gas phase OH reaction
field work
product formation mechanisms
gas phase OH reaction rate constants
chemical processing
aerosol phase processing
flow tube chemical ionization mass spectrometry technique
fate
OH Reaction
OH rate constants
MCM v 3.2.
rate Constants
product mechanism
gas phase oxidation
SOA conditions
IEPOX species
2013-11-19 00:00:00
Journal contribution
https://acs.figshare.com/articles/journal_contribution/Rate_Constants_and_Products_of_the_OH_Reaction_with_Isoprene_Derived_Epoxides/2351941
Recent laboratory
and field work has shown that isoprene-derived
epoxides (IEPOX) are crucial intermediates that can explain the existence
of a variety of compounds found in ambient secondary organic aerosol
(SOA). However, IEPOX species are also able to undergo gas phase oxidation,
which competes with the aerosol phase processing of IEPOX. In order
to better quantify the atmospheric fate of IEPOX, the gas phase OH
reaction rate constants and product formation mechanisms have been
determined using a flow tube chemical ionization mass spectrometry
technique. The new OH rate constants are generally larger than previous
estimations and some features of the product mechanism are well predicted
by the Master Chemical Mechanism Version 3.2 (MCM v3.2), while other
features are at odds with MCM v3.2. Using a previously proposed kinetic
model for the quantitative prediction of the atmospheric fate of IEPOX,
it is found that gas phase OH reaction is an even more dominant fate
for chemical processing of IEPOX than previously suggested. The present
results suggest that aerosol phase processing of IEPOX will be competitive
with gas phase OH oxidation only under SOA conditions of high liquid
water content and low pH.