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Quantification of alkenes on indoor surfaces and implications for chemical sources and sinks
Author(s) -
Deming Benjamin L.,
Ziemann Paul J.
Publication year - 2020
Publication title -
indoor air
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.387
H-Index - 99
eISSN - 1600-0668
pISSN - 0905-6947
DOI - 10.1111/ina.12662
Subject(s) - alkene , microscale chemistry , chemical composition , chemistry , environmental chemistry , sink (geography) , indoor air , chemical engineering , materials science , environmental science , organic chemistry , environmental engineering , engineering , mathematics education , mathematics , cartography , geography , catalysis
Indoor surfaces are known to support organic films, but their thickness, composition, and variability between environments remain poorly characterized. Alkenes are expected to be a significant component of these films, with the reaction with O 3 being a major sink for O 3 and source of airborne chemicals. Here, we present a sensitive, microscale, nanospectrophotometric method for quantifying the alkene (C=C bond) content of surface films and demonstrate its applicability in five studies relevant to indoor air chemistry. Collection efficiencies determined for a filter wipe method were ~64%, and the overall detection limit for monoalkenes was ~10 nmol m −2 . On average, painted walls and glass windows sampled across the University of Colorado Boulder campus were coated by ~4 nm thick films containing ~20% alkenes, and a simple calculation indicates that the lifetime for these alkenes due to reaction with O 3 is ~1 hour, indicating that the films are highly dynamic. Measurements of alkenes in films of skin oil, pan‐fried cooking oils, a terpene‐containing cleaner, and on various surfaces in a closed classroom overnight (where carboxyl groups were also measured) provided insight into the effects of chemical and physical processes on film and air composition.